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Chapter 4: Conceptual Science Teaching

1. CHINA KEEPS THE TEA HOT E m Explanation The issue here is how quickly thermal energy travels through or is lost from different materials Energy loss from the teapot will depend on the thickness it takes more energy to warm a thicker teapot the nature of the material metals are good conductors of energy the colour dark colours lose energy more quickly and how shiny it is dull surfaces lose energy more quickly The interaction of the different factors is difficult to predict accurately The situation can be investigated using real teapots full of hot water and measuring the rate of cooling with a thermometer It can be modelled using containers of different materials filled with hot water which can allow the effect of each factor to be analysed separately The physics experiment guide describes a useful experiment where students work together to make the best insulating bottle Student Centred Approaches for Science Education Part 2 60 27 Windy day Link with curriculum Grade 10 chapter 2 lesson 3 2009 THE WIND FEELS COLD WINDY DAY CS NAYLOR AND B KEOGH BECAUSE MORE WATER THE WIND TAKES EVAPORATES FROM YOUR SKIN AWAY THE WARMER AIR FROM ROUND THE AIR PARTICLES ARE YOUR BODY MOVING FASTER SO THE WIND SHOULD FEEL WARM Explanation e The wind feels cool because it encourages faster evaporation from the surface of the skin By blowing away the layer of moist air which usually surrounds
2. Since 6 fingers are dominant over 5 fingers Why don t most people have 6 fingers I m glad have six fingers I m a guitar There is no real advantage to having 6 fingers so it ll never be common But we know that having 6 fingers is caused by a mutation and mutations are always bad t s just a matter of time Dominant genes always take over in a population Fisher Anderson 7 2 Explanation Character A has the best answer A trait typically becomes more common if there is some advantage to organisms that have that trait Answer C reflects a common idea among students that dominant alleles are somehow stronger Answer B is irrelevant and answer D brings up the erroneous but very common idea that mutations always have negative effects Another example of a dominant but rare trait is dwarfism Student Centred Approaches for Science Education Part 2 82 48 Use amp Disuse Link with curriculum Grade 12 chapter 6 lesson 2 2010 What happens when body parts aren t used Not true As long as the genes remain the same the wings will stay the same too That means Each succeeding your wings are generation will have going to atrophy smaller weaker wings We hardly Fisher Anderson m Explanation E Answer C is the best choice since genes do not just go away Both A and B may be popular student
3. Link with curriculum Grade 10 chapter 1 lesson 4 2009 amp Grade 7 chapter 4 lesson 3 2009 MOON ROCK S NAYLOR AND B KEOGH THE ROCK WON T SINK IN THE WATER BECAUSE IT DOESN T WEIGH AS MUCH HERE ON THE MOON THE ROCK WILL SINK SUST LIKE IT DOES ON EARTH I THINK IT WILL SINK BUT MORE SLOWLY THAT IT DOES ON EARTH Explanation Since the rock weighs less on the Moon than on Earth we would expect it not to sink However its mass and its volume are the same so its density has not changed The same is true for the water it weighs less but its density has not changed Therefore the relationship between the density of the rock and the density of the water has not changed So the rock will sink on the Moon like it does on Earth Since the force of gravity on the Moon is smaller than on Earth the rock will sink more slowly We cannot practically investigate the situation since we cannot escape the Earth s gravity A range of activities and experiments to develop a thorough understanding of floating and sinking should enable intelligent predictions to be made about what would happen on the Moon Student Centred Approaches for Science Education Part 2 54 21 Hot air balloon Link with curriculum Grade 8 chapter 2 lesson 3 2010 THE BALLOON WILL BE LIGHTER WHEN WE EAT THE FOOD DON T EAT THE PICNIC THE EXTRA FOOD WILL MAKE US HEAVIER AND THE BALLOON WILL SINK WE CAN EAT T
4. Making students ideas explicit so that potential misconceptions can be identified Challenging and developing students ideas Illustrating alternative viewpoints Teaching students to ask scientific questions Student Centred Approaches for Science Education Part 2 14 Providing starting points for investigation students set up an experiment to verify different Opinions expressed in the cartoon Deepening understanding of science concepts 3 Material Qe The cartoons must be clearly presented in the classroom A projector is very useful but if this is not available you can also provide a copy of the cartoon for the students Depending which cartoon you will use and how you will use it you may need some additional material such as Empty sheets so students can take notes Experiment material needed for investigation see description of cartoons 4 Methods You can integrate concept cartoons in your lessons through various student centred approaches Four ways to apply concept cartoons in class are described in detail using examples on the topic shadows Each teaching method integrates a concept cartoon in a student centred way Try some other cartoons following the examples below Student Centred Approaches for Science Education Part 2 15 4 1 Class Discussion Introduction k You can introduce concept cartoons and tests to students through class discussion This technique is
5. 10 Soil 12 Recycling 2 Stars 11 Mountains 13 Why is a day 24 hours 3 Why does the Moon Shine 14 Acid Rain Student Centred Approaches for Science Education Part 2 4 Daytime Moon 5 Moon Shape 6 Dark side of the Moon 7 Moon Boots 8 Space Walk 9 Lunar eclipse Each cartoon is described in detail in Annex 3 6 4 Chemistry For chemistry we include 11 model concept cartoons covering a wide range of topics from the curriculum Mixtures compounds states of matter acids and bases chemical reactions 1 Liquids 7 Acidic oranges 8 Rusty nails 2 Scrambled eggs 9 Rusty nails 2 3 Muddy waters 10 Aspirin 4 Condensation 11 Burning Candle 5 Sweet tea dissolving 6 Melting Ice Each cartoon is described in detail in Annex 4 Student Centred Approaches for Science Education Part 2 7 Variations 745 v uk 4 There more ways to use concept cartoons your lessons Some examples Blank out some speech bubbles and let students complete them Create your own concept cartoons by collecting students ideas Let groups of student teachers create their own cartoons that reflect the range of ideas in their group Advanced student teachers can create their own cartoons to illustrate possible sources of confusion on a topic Cartoons can be used as an opening statement to apply reasoning skills such as Agreement Circl
6. Part 2 95 60 Stars Link with curriculum Grade 7 chapter 1 lesson 2 2009 The stars disappear in the daytime because They Go round to the other side of the Earth they only reflect moonlight 5 Naylor B Kei They down when the sun nes e Explanation E Lj Unlike the Moon stars generate their own light by nuclear fusion They are still present in the sky during the daytime so the question of why they are not visible is a real one Very little light from the stars reaches the Earth because they are so far away The Sun is so much brighter by comparison that the small amount of light from the other stars cannot be seen during the daytime The situation cannot be investigated through practical activity Enquiry can include a range of thought experiments and reasoning by analogy Student Centred Approaches for Science Education Part 2 61 Why does the Moon shine Link with curriculum Grade 8 chapter 3 lesson 2 2010 Eep e e VCI Es a Se IR hi 5 e Look how brightly It doesn t shine the moon shines it refiects light from the sun I think it stores light during the daytime and releases it at night It doesn t shine it reflects light from the Earth Explanation f A common misconception is that the Moon is a source of light like the Su
7. SHADOW THE ORANGE FILTER MAKES AN ORANGE HADOW THE FILTER DOESN T MAKE ANY SHADOW THERE IS ONLY LIGHT Objectives To detect student teachers misconceptions With respect to the concept shadow students may e that shadows are always black e confuse shadow and light Tolet student teachers find valuable aspects in different viewpoints Depending on the definition used and the conditions multiple conceptual views can be correct Tolet students use experimental investigations to deal with scientific questions and obtain valuable conclusions Tolet student teachers construct a definition of shadows in their own words Tolet student teachers understand that the conceptual difference between shadows and light is small Student Centred Approaches for Science Education Part 2 26 Material needed F Concept cartoon amp Optional for this concept cartoon 2 6 light sources flashlights or light bulbs A projector is good light source for class discussions Common materials like plastics coloured papers Step by step instructions 1 Introduce the topic and present the concept cartoon Allow for a short period of individual reflection while each student reads all statements Then ask students which view they agree with e g by raising hands or with voting cards 2 Encourage discussion in small groups 2 to 5 students and stim
8. Uncovering Student Ideas in Science 25 Formative Assessment Probes Vol 2 NSTA Press Keeley P et al 2009 Uncovering Student Ideas in Science 25 Formative Assessment Probes Vol 4 NSTA Press Mazur E 1997 Peer Instruction A User s Manual Prentice Hall McDaniel M A and Donnelly C M 1996 Learning with Analogy and Elaborative Interrogation Naylor S Downing B and Keogh B 2001 An empirical study of argumentation in primary science using Concept Cartoons as the stimulus Third International Conference of the European Science Education Research Association Thessaloniki Greece Naylor S and Keogh B 2000 Concept Cartoons in Science Education Millgate House Publishers Tweed A 2009 Designing Effective Science Instruction NSTA press Arlington Virginia USA Student Centred Approaches for Science Education Part 2 Websites Physics http galileo harvard edu Chemistry http www chem wisc edu concept http www chemcollective org find php Earth and environmental science http serc carleton edu resources 1302 html Assessment and Active Learning Strategies for Introductory Geology Courses http serc carleton edu resources 21699 html Using ConcepTests to Assess and Improve Student Conceptual Understanding in Introductory Geoscience Courses http serc carleton edu introgeo interactive ctestexm html Concept Tests for many earth science topics 140 vob cc w
9. Why is a day 24 hours Link with curriculum Grade 7 chapter 2 lesson 1 amp 2 2009 The un travels Tho Earth travels round the Earth round the sun once once every 24 hours every 24 hours E 5 am z un a The moon travels round the Earth once ne Farth spins once every 24 hours every 24 hours Explanation d A ia Day and night are caused by the Earth rotating on its axis so that the apparent position of the Sun the sky changes The rotation occurs every 24 hours resulting in the 24 hour cycle of light and dark Although it appears that the Sun travels across the sky this is because we are not aware of the rotation of the Earth so we attribute the change in position of the Sun to the Sun moving rather than to the Earth moving It is not easy to prove experimentally that the Earth rotates every 24 hours rather than the Sun moving The situation can be modelled using a globe and strong light source Thought experiments and predictions can be linked with everyday experience of day and night Student Centred Approaches for Science Education Part 2 107 70 Acid Rain Link with curriculum Grade 12 chapter 1 lesson 3 2011 Why don t the hiis disspive in the aod an If the hills are made The rock ts too hard to dissoly of chalk they wil D ssolve and i 1 OSA Explanation C Many types of rock are soluble to some extent
10. COAT ON THE SNOWMAN rtevelde IT WILL MELT HIM NO THIS COAT WILL hogeschool HELP THE SNOWMAN imt ain tern NOT TO MELT I DON T THINK THE COAT WILL MAKE ANY DIFFERENCE e Explanation a A common misconception is that some materials have the property of making things warm Wearing a coat keeps us warm and causes a belief that it will also make the snowman warm and melt quickly In fact the coat acts as an insulator reducing the movement of energy in either direction On a person it can prevent energy loss while it prevents the snowman from getting warmer The snowman will therefore not melt easily while wearing a coat The situation can be investigated using ice Water can be frozen inside plastic drinks bottles or plastic containers and used as model snowmen An old sock or cloth will make a model coat and allow the effect of the coat to be investigated A useful extension is to investigate the effect of other factors such as the nature colour and thickness of the coat Student Centred Approaches for Science Education Part 2 59 26 Teapot Link with curriculum Grade 7 chapter 2 lesson 1 2009 TEAPOT S NAYLOR AND B KEOGH rtevelde THE TEA WILL STAY HOT IN A hogeschool METAL TEAPOT BECAUSE THE Pea ee ote SHINY METAL KEEPS THE TEA ALL TEAPOTS KEEP THE TEA AT THE SAME TEMPERATURE THE TEA WILL e IT DOESN T MATTER STAY HOT WHAT TEAPOT YOU BECAUSE THE USE THICK
11. OF THE EARTH FALLS ON THE p Explanation E An eclipse of the Sun occurs when the Moon passes between the Earth and the Sun so that the Moon blocks out the Sun s light and the Earth is in the Moon s shadow This happens rarely because the three bodies need to line up precisely It can only happen with the Moon s shadow since no other planetary body is close enough to the Earth to block out the Sun s light This is quite different from a lunar eclipse which occurs when the shadow of the Earth falls on the Moon so that the Moon can no longer reflect light from the Sun It is not easy to prove this experimentally Understanding can be developed with a model or simulation The situation can be modelled using a globe and strong light source with a small ball to represent the Moon Student Centred Approaches for Science Education Part 2 41 8 Moving shadow Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 SHADOW OF THE SUN CO DE POORTER BASED ON S NAYLOR ANO B KEOGH THE SHADOW MOVES FASTEST IN THE MIDDLE i THE SHADOW TAKES 12 OF THE DAY N T HOURS TO GO ALL THE WAY rtevelde ln on Explanation E The Earth rotates around its axis every 24 hours so it will take 24 hours for the shadow of the stick to return to its original position there is no shadow during the night Even though the Sun s position in the sky varies the speed of movement of the shadow round the stick is c
12. Virak Ms Nget Sokhany Teacher Trainers RTTC Kandal Minister Ministry of Education Youth and Sport Secretary of state Ministry of Education Youth and Sport Director Teacher Training Department Director Department of Curriculum Development Director General Secondary Education Department SEAL Programme Coordinator RTTC Kandal SEAL Programme Coordinator RTTC Kandal Technical Advisor Facilitator Science amp life skills RTTC M amp E Officer Facilitator SEAL Programme Mr Mam Pha OI Mr Meng Phirun Mr Thak Sophea Mr Be Bra Mr Sok Saroeun Mrs Long Punthiny Ms Hou Chansara Mrs Som Dany Mr Oeur Sokmeng Mrs Srey Chansophea Ms Veng Sreymon Mr Seang Bunthoeun Teachers Hun Sen Sereypheap High school Kandal Province Mrs Kong Sovannra Pang Sienghay Mrs Sun Chanmoly Mrs Pen Raksmey Student Centred Approaches for Science Education Part 2 Teachers Anuwat Lower Secondary School Kandal Province Mrs Loch Sotheany Mrs Mam Metboran Mrs Morn Sokha Mr Phan Ny Teachers Hun Sen Takhmao High school Kandal Province Mr Prum Vannara Mrs Tuon Vannak Mrs Phon Socheat Teachers Hun Sen Kampong Kantuot High school Kandal Province Mr Men Nimol Mrs Ek Amara Mrs Chea Yeth Ms Tim Bunthen Editorial Committee Mr Men Vannary Officer Teacher Training Department Mr Sok Saroeun Officer Teacher Training Department Mr Sin Vath Officer Teacher Training D
13. When an ice cube at 4C is placed in a cup at room temperature the surface of the solid cube absorbs thermal energy from the surroundings The energy is used to overcome the attractive forces between the water molecules When sufficient energy is absorbed the solid ice begins to melt For water this phase change occurs at OC During a phase change the temperature will remain constant as long as both phases are present Temperature heat and thermal energy are related but distinctive terms that are easily mixed up by students Be careful to make a correct distinction Example 20 Mechanics Link with curriculum Physics Grade 8 chapter 1 lesson 1 amp 2 2010 Two cars one twice as heavy as the other are at rest on a horizontal track A person pushes each car for 5s Ignoring friction and assuming equal force exerted on both cars the momentum of the light car after the push is A Smaller than B Equal to C Larger than The momentum of the heavy car The correct answer is B The change in momentum caused by a constant force is the product of the force and the time interval Ap F At Because the time interval At and the force are the same for both cars the changes in momentum are also equal Example 21 Mechanics Link with curriculum Physics Grade 8 chapter 1 lesson 1 amp 2 2010 Student Centred Approaches for Science Education Part 2 134 Two cars one twice as heavy as the other are at rest on a horizontal track A per
14. always changes Students may notice correctly that the size of a shadow doesn t change if you move around in Sunlight The Sun is a light source at a great distance The light rays from a distant source travel parallel With the same drawing as before but using parallel rays you can demonstrate that the size doesn t change Figure The shadow doesn t change with a distant light source Source Wikipedia 4 Your shadow will disappear when you are close to the lamp When you cover the light source completely the shadow spreads itself over the whole wall or classroom The shadow doesn t disappear but everything becomes shadow Some students may think that the shadow disappears because the boundary between light and shadow is gone With this statement you can start an in depth discussion about the definition of the concept shadow You can start this discussion with the following question What is the difference between covering the light source totally and putting the lights out Actually both situations have the same effect In the first situation we speak about shadow but in the second situation we don t This starts the discussion about the nature of a shadow When do we call darkness a shadow Why don t we think about shadows all situations where there is darkness Student Centred Approaches for Science Education Part 2 18 Conclusion This concept cartoon shows the need for a good description or definition of
15. chapter 3 lesson 2 2010 X X The moon appears te change shape because of the Earth s shadow oan moor x m z We only see the part Part of the moon is e of the moon that is lit Sometimes covered by clouds i e Explanation u A common misconception is that the change in the Moon s shape is due to the shadow cast by the Earth In fact when the Earth does cast a shadow on the Moon it causes a lunar eclipse and lunar eclipses do not happen every month We only see the part of the Moon that is lit by the Sun and as the relative positions of the Moon Earth and Sun change the appearance of the Moon will be different to an observer on the Earth any observer will see the same shape though at a given time You can help students to understand this concept through low cost models or simulations The situation can be modelled with a globe and strong light source and a small white ball to represent the Moon By altering the relative positions of the Moon Earth and Sun it is possible to model the various phases of the Moon when viewed from the Earth as different sections of the Moon are illuminated Student Centred Approaches for Science Education Part 2 99 64 Dark Side of the Moon Link to curriculum Grade 8 chapter 3 lesson 1 2010 Explanation A tf Although we talk about the dark side of the Moon in reality the Moon does not have a dark side The Moon rotates once for each orbit arou
16. choices and actually body parts that are not used may atrophy assuming that they were functional at some point Students often incorrectly believe that use or disuse of an organ can lead to species changes evolution The driving force behind the loss of an organ is not due to a need but to the proportion of individuals with or without the trait surviving to the next generation Because the trait may not be needed it doesn t give an evolutionary advantage to have one so the disappearance of the trait is not a disadvantage to the species Recent research in genetics makes the distinction between the presence of genes and the expression of genes A gene for wings may still be present in an animal s genome but not be expressed anymore which means that the gene is no longer activated Although this is too advanced for the curriculum it s good to keep it in mind Student Centred Approaches for Science Education Part 2 83 49 Adaptation Link with curriculum Grade 12 chapter 6 lesson 1 2010 What is Darwinian adaptationd am adapting c to this hot weather by drinking ony n ulations can lots of water and dart ike oe This heat staying relaxed cacti have over many bothers me but years think I ll adapt in a few days You and know how to adapt but plants are not that Explanation e b Answer B is correct because only populations can adapt Answers A and C are incorrect because they refer to ind
17. e ee eene dede 16 4 2 Group Discussion 2 2 25 deed o ege aed Die e deed dee D ene d e a eee 20 4 3 Experimental ene 23 4 4 Group discussion combined with experimental investigation 26 5 When to use concept a E a a a nennen enne 29 6 Examples from the curriculum a nenne 29 6 1 PHYSICS 29 6 2 BIOlOgy ea han nen cu 30 6 3 Earth and environmental science sssssssseeseeenenen eene nnne 30 6 4 n e A t 31 Te sMallations dne ote et eds Pr e ue E tee e rut t ee RE Bet e Ere Pt de e 32 8 Important tps rte cene nae aa cede ve dee doe ee dee eee deas 32 Annex 1 Concept Cartoons for Physics eene nre en nennen nnne nennen nnn 33 ERE 33 34 The White Cat inet ame o Eo Red e En te ue E eee ed Eod 34 S ndglasses aun cns dU C eode decre nte dieit e a e qp notae eg 35 Shadow SCreen etta ee EQ a ested eek 36 Student Centred Approaches for Science Education Part 2 4 Shadows at night cceesccccceeeesneceeneeeeeeeeeeeeeeeaaeseeaaeeaeeeseaesseaaesgeeeeeneeesaeseeaaesseeeesseeeas 37 TWOMIOOS eniin eite ae
18. in acids The acidity of rainfall varies according to the location the prevailing winds and the presence of industrial pollutants Even very dilute acids can dissolve some rocks especially limestone chalk and marble given sufficient time and more concentrated acids can dissolve some rocks more quickly Most geological processes are too slow to be noticed including hills dissolving in acid rain but this does not mean that they are not occurring Acid rain occurs naturally by volcano eruptions and lightning but is enhanced by human activity such as the release of SOx and NOx in the atmosphere The situation can be modelled using samples of different types of rock and treating them with dilute acids preferably over a period of several days The acidity of rain water can be measured in the chemistry lesson Student Centred Approaches for Science Education Part 2 108 Annex 4 Concept Cartoons for Chemistry Disclaimer The cartoons in this manual have been developed by Arteveldehogeschool based on the work from Naylor and Keogh For the Khmer version translated and locally drawn cartoons were used The cartoons are copyright protected and cannot be distributed outside RTTCs without written permission of the copyright holder y Introduction FT For each cartoon we describe the scientifically correct viewpoint and possible misconceptions of the students Moreover we suggest ideas for investigations experiments an
19. light however these surfaces won t reflect any light either and remain invisible The cat s eyes and its fur do not generate light themselves so neither can be seen in complete darkness Access to a completely dark room is necessary to test the different possibilities A windowless room is ideal alternatively it may be possible to create a dark room with a very large cardboard box Care needs to be taken to exclude all light A variety of reflective surfaces could be tested e g coins mirrors aluminium foil to show that there is a consistent and predictable pattern for when objects can be seen Student Centred Approaches for Science Education Part 2 34 2 Sunglasses Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 SUNGLASSES S NAYLOR AND B KEOGH DON T FORGET YOUR SUN GLASSES THE SNOW THE SNOW TRAPS PRODUCES A LOT OF LIGHT LIGHT AND THE SNOW 3UST REFLECTS LIGHT FROM GRADUALLY THE SUN IT S THE MIDDLE OF WINTER DON T NEED SUNGLASSES NOW Explanation e i x UW i People at the beach may be surprised how easily they get Sun burnt by Sunlight reflecting off the sand The reflection from the sand increases the total amount of Sunlight striking the body so wearing Sunscreen and Sunglasses is important However all light comes from the Sun The snow itself does not produce or store any light but simply reflects it Sun Snow and sand reflect light better than soil and grass Student C
20. oxygen in the air to form iron oxide rust The actual change of weight in the nails can be investigated A useful extension is to find out where the additional weight came from In a sealed jar the total weight of the jar plus nails will be constant even though the nails increase in weight Setting up the situation with nails in a jar with a gas such as carbon dioxide you can do this with a candle will show that oxygen is essential for rusting to occur Student Centred Approaches for Science Education Part 2 118 79 Aspirin Link with curriculum Grade 7 chapter 2 lesson 2 2009 The bubbles don t take up any space when How do all those bubbles fit inside one Alka Seltzer tablet they are solid x e E m 5 The bubbles are in The bubbles are the water not in the made by a chemical tablet reaction Explanation e tG When the aspirin tablet and water react they end up in a different physical state changing from a solid and a liquid to a solution and a gas However the rapid production of gas suggests that this is more likely to be a chemical reaction not just a change of state Whereas changes of state are easily reversible many chemical reactions are not such as the reaction between aspirin and water A useful line of enquiry is to find examples of similar types of reaction such as that between vinegar and baking powder Determining the gas in each case will help to sho
21. situation is similar to the skateboard but without any friction acting The situation cannot be investigated directly but enquiry can include a range of thought experiments What would happen if predictions and modelling aspects of the situation as far as possible e g horizontal motion in situations where there is very little friction Student Centred Approaches for Science Education Part 2 52 19 Fast plane Link with curriculum Grade 8 chapter 1 lesson 2 2010 FAST PLANE BASED ON S NAYLOR AND B KEOGH IF ONE OF THE THE BLUE AIRPLANE PLANES HAS A HAS A GREAT BETTER ACCELERATION SO IT ACCELERATION WILL GET HOME HEN IT MUST HAVE QUICKLY THE OTHER PLANE HBS A HIGHER TOP A HIGHER TOP SPEED SO THAT WILL GET SPEED AS WELL HOME FASTER Explanation e The issue here is the relationship between acceleration speed and journey time Journey time depends on average speed not acceleration Although good acceleration is useful for the plane to get up to cruising speed quickly it will not make much difference to the journey time except over very short distances Having good acceleration does not necessarily mean that the top speed is greater or that the journey time will be noticeably less Enquiry can include calculating journey times in a range of situations drawing distance time graphs and the use of computer simulations Student Centred Approaches for Science Education Part 2 53 20 Moon rock
22. the bottle can be weighed before and after the cap is removed Student Centred Approaches for Science Education Part 2 67 34 Mountains Link with curriculum Grade 7 chapter 4 lesson 4 2009 IT S HARD TO BREATHE UP HERE BECAUSE THERE AREN T MANY AIR PARTICLES I THINK THE AIR PARTICLES ARE SMALLER BECAUSE IT IS SO COLD THE COLD MAKES IT HARDER TO BREATHE IN I THINK AIR PARTICLES HEAVY SO THEY FALL DOWN THE MOUNTAIN Explanation The issue here is the nature of air particles and where they are The air particles do not change depending on temperature or altitude but there are fewer air particles at higher altitudes Although individual air particles are moving around randomly at high speeds they are still attracted to the Earth by the force of gravity so there will be more particles at the bottom of the mountain than at the top This is why the Earth s atmosphere only takes up a relatively narrow band around the Earth s surface There are no obvious practical investigations to test this situation Enquiry is likely to focus on reasoning from experience and by analogy Predicting what would happen if each of the statements were correct is a useful thought experiment Student Centred Approaches for Science Education Part 2 68 Electricity 35 Switch Link with curriculum Grade 7 chapter 3 lesson 6 2009 SWITCH CS NAYLOR AND B KEOGH THE SWITCH NEED
23. the concept shadow Moreover students are stimulated to think about scientific concepts and how to test their hypothesis A first conclusion is that in order to have a shadow you need a light source and an object A second conclusion can be that a shadow is the place where there is no light from the light source The step by step instructions illustrate that it is important to discuss all the statements in the cartoon also the ones that are not correct Students need to be stimulated to think about the statements to argue why they are not correct try to design experiments to test the validity of the statements and formulate definitions of concepts in their own words Student Centred Approaches for Science Education Part 2 19 4 2 Group Discussion Introduction You only reach the full potential of concept cartoons and concept tests by providing the opportunity for student teachers to discuss them in small groups This allows for students to discuss their viewpoints with their peers They can practice their argumentation and listen to alternative viewpoints This kind of collaborative learning can be a very powerful experience We discuss this technique with a similar example on the topic of shadows t THERE ARE NO THERE ARE SHADOWS AT NIGHT SHADOWS AT NIGHT BUT YOU CAN NOT SEE THEM Be EVERYTHING IS SHADOW AT NIGHT SHADOWS LOOK DARKER AT NIGHT Objectives A To detect student teachers misconceptions So
24. their density and placement of the leaves The place where the shadows of two trees overlap will be a bit darker The leaves of the first tree block only part of the light The rest of it passes through but can be stopped by the leaves of the second tree Since the overlapping shadow is caused by a double amount of leaves the shadow will be a bit darker If the experiment from answer 2 is repeated but now with transparent materials like tracing paper or a piece of a mosquito net this situation will become clear Conclusion The previous definition of the concept shadow has to be changed A shadow appears when the light from a light source is totally or partially blocked by an object In this cartoon the concepts of light and shadow meet for the first time In the last experiment you can ask students the thinking question What do we call the spot behind a transparent object Is it light or shadow Student Centred Approaches for Science Education Part 2 25 4 4 Group discussion combined with experimental investigation Introduction gt This method lets students work more independently They discuss the concept cartoon set up a plan for experimental investigation execute it and report on the conclusions It provides students with a strongly authentic learning experience and stimulates collaborative learning THE COLOUR OF SHADOWS BASED ON S NAYLOR AND B KEOGH A f rtevelde THE ORANGE CARD hogeschool MAKES AN ORANGE EN
25. weight does not change Ten grams of ice will melt to give ten grams of water However the volume does change when the ice melts Ten grams of water take up less space than the ten grams of ice so the density of the ice is less than the density of the water There is plenty of scope for confusion here The water and ice are exceptional in that almost all other substances get denser as they solidify The weight of a given amount of ice can be measured before and after melting to see whether or not the weight changes Exploring how density alters with changes of temperature is more interesting and can lead to discussions e g In the fishbowl on why icebergs float where ice forms as water is freezing and how fish manage to survive over the winter when ponds freeze Student Centred Approaches for Science Education Part 2 62 29 When water is boiling Link with curriculum Grade 10 chapter 2 lesson 3 2009 YOU CAN SEE WHEN WATER IS BOILING BUBBLES OF CS ANAYLOR AND B KEOGH rtevelde HEAT IN THE hogeschool BOILING WATER aiai THERE ARE IMPURITIES COMING OUT OF 3 THE WATER I THINK THEY ARE BUBBLES OF AIR I THINK THEY ARE BUBBLES OF OXYGEN ANO HYDROGEN I THINK THEY ARE BUBBLES OF WATER TURNED INTO GAS Explanation Pe Most students are familiar with bubbles in boiling water but what makes up the bubbles is less well understood Many think that liquids bo
26. 6 Students obtain experience in using scientific terminology and concepts 7 The teacher receives immediate feedback about the level of understanding in the class and present misconceptions Student Centred Approaches for Science Education Part 2 121 Another term used for peer instruction is Think Pair Share First students think about the answer then they pair in small groups to discuss and finally they share their thoughts with the class What are the advantages of peer instruction compared to traditional hands up methods 1 Every student has the chance to rehearse their answer verbally to his her partner before having to speak out in class 2 Afterwards far more students become willing to put up their hands to reply 3 How many disappointed looks do you get when a student is bursting to tell you the answer and you choose someone else They can now turn to their partner and explain him her the answer 4 Rehearsing their response means they can compare what they thought with the answers that are given If they have not understood they will become aware of this and try to make sense of their confusion 2 Objectives The objectives of Concept tests are similar to those for Concept Cartoons They aim at focusing students attention on underlying concepts See also the paragraph on Why Peer Instruction 3 Material needed b a Ee LS 33 z No material is needed The method can be us
27. 9 Shadow of the Sun size 10 Curved mirror 11 Prism 12 Torches 13 Mirror box 14 Bungee jump 15 Falling 16 Skateboard 17 Soccer 18 Space rocket 19 Fast plane 20 Moon rock 21 Hot air balloon 22 Space walk 23 Ski slope 24 Boiling water 25 Ice and cloth 26 Teapot 27 Windy day 28 Melting ice 29 When water is boiling 30 Ice cubes 31 Helium balloon 32 Balloon 33 Lemonade 34 Mountains 35 Switch 36 Current flow 37 Thicker wires 38 Longer wires 39 Electromagnet Student Centred Approaches for Science Education Part 2 29 6 2 Biology We selected 19 cartoons covering a wide range of topics from the curriculum Plants human body evolution amp reproduction genetics 1 Growth direction of 5 Headstand 8 Dominance 18 Genes plants 6 Babies 9 Use and Disuse 19 Acquired traits 2 Seeds in the dark 7 Antibiotics 10 Adaptation 3 Heavy plants 11 Competition 4 Rotten apple 12 Reproduction 13 Resistance 14 Pond Life 15 Variation 16 Variation 2 17 Timeline of natural selection Each cartoon is described in detail in Annex 2 6 3 Earth and environmental science For Earth and environmental science we include 14 model concept cartoons covering a wide range of topics from the RTTC curriculum solar system amp Universe physical geography Earth amp Environment 1 Is it Dark in Space
28. Antibiotic resistance is the next natural step for bacteria This stage just happens to be occurring now Student Centred Approaches for Science Education Part 2 135 C Now that many people use antibiotics most non resistent bacteria are dead Most of the bacteria that are left are resistant D Individual bacteria that are exposed to antibiotics over and over eventually become resistant Answer C is correct It contains the idea of random mutations Mutations that are strengthening the bacteria s chance on survival and reproduction here resistance to antibiotics will become more dominant in the population The other options consider the development of resistance as a kind of deliberate process or suggest that bacteria can somehow decide to become resistant 7 Important tips e How to make your own concept tests There are no strict rules for Concept tests but they should at least fulfil some basic criteria e Focus on a single scientific concept Otherwise it is difficult to interpret wrong answers e question shouldn t rely on equations or on memorized facts such as numbers e various answers should reflect common misunderstandings with students e questions should be unambiguously worded e question shouldn t be too easy or too difficult in general a correct response share between 40 and 80 indicates a right difficulty level In general it s very difficult for a teacher to identify miscon
29. HE PICNIC WHENEVER WE WANT AND IT WON T MAKE ANY DIFFERENCE TO THE WEIGHT hh Explanation wy This concept cartoon raises the question of conservation of mass Is the amount of food the same whether it is outside or inside the body Of course eating the food will not make any difference to the overall weight of the balloon and passengers It could be argued that over longer periods of time the food is metabolised and most of it ends up as carbon dioxide and water both of which are breathed out from the lungs so the balloon and passengers must slowly get lighter It is not possible to directly test this with a hot air balloon but thought experiments and predictions involving similar situations are a useful line of enquiry Student Centred Approaches for Science Education Part 2 55 22 Space walk Link with curriculum Grade 8 chapter 2 lesson 2 amp 3 2010 IF I PUSH OFF I WILL FLOAT FOR EVER rtevelde hogeschool I YOU WILL PUSH GENTLY YOU WILL SOON STOP YOU WON T BE ABLE TO PUSH OFF THERE IS NO FRICTION IN SPACE YOU DON T NEED TO WORRY THE GRAVITATIONAL ATTRACTION OF THE ROCKET WILL BRING YOU BACK Explanation a A good understanding of how forces operate is vital for astronauts who make a spacewalk Pushing off in any direction will result in the astronaut just floating away since there is virtually no air resistance to prevent movement It will the
30. Kingdom of Cambodia Nation Religion King Student Centred Approaches for Science Education Part 2 Chapter 4 Conceptual Science Teaching P met ven a ee Cj de i 1 i XU M e e ny Teacher Training Department 2012 Chapter 4 Conceptual Science Teaching Published by the Ministry of Education Youth and Sport of the Kingdom of Cambodia Printed in Cambodia 2013 First edition The development and publication of this document has been funded by the General Directorate for Development Cooperation and Humanitarian Aid DGD with technical support from the Flemish Association for Development Cooperation and Technical Assistance VVOB The Flemish and the Belgian governments cannot be held responsible for the content of this publication Copyright Notice Unless otherwise noted in the materials excluded and rights reserved list below material in this publication is licensed under a Creative Commons Attribution NonCommercial ShareAlike 3 0 Unported License This means that you may distribute copy remix and build upon this work non commercially without prior permission of the publisher as long as you credit and license your new creations under identical terms More information on this license is available at http creativecommons org licenses by nc sa 3 0 Material excluded and rights reserved Some material in this publication is not being made available under the terms of this license Thes
31. S TO BE ON THE OTHER SIDE OF THE LAMP THE SWITCH buco rs THE SWITCH CAN AND OFF BE ANYWHERE IN THE CIRCUIT TO URN THE LAMP ON Explanation T A common misconception is that electricity starts at the battery and goes through each component of the circuit in turn so that a switch needs to be on the positive side of the lamp in order to turn it on and off The electricity flows in all parts of the circuit at the same time so the switch could be anywhere in the circuit and it would still have an effect on the lamp The problem shown in this circuit can be investigated with simple practical equipment Arranging a Switch in different places in a simple circuit is sufficient to clarify the effect of changing the location of the switch Student Centred Approaches for Science Education Part 2 69 36 Current flow Link with curriculum Grade 7 chapter 3 lesson 2 2009 THE ELECTRIC CURRENT IS CURRENT FLOW A THE SAME IN BOTH WIRES 9 NAYLOR AND B KEOGH 7 4 THERE 15 MORE ELECTRIC N CURRENT IN THE WIRE GOING TO THE LAMP I THINK THERE IS MORE ELECTRIC CURRENT IN THE WIRE COMING FROM THE LAMP Explanation e T Since batteries go flat something must be being used up in electrical circuits It therefore seems reasonable to suppose that there will be more electric current going to the lamp than going away from it The fact that the current is the same in both wires seems counterintuit
32. T KEEPS HIM MOVING IF THE FRICTION IS VERY SMALL HE WILL KEEP ON MOVING HE ISN T PUSHING SO THERE CAN T BE ANY FORCE SKATEBOARD CS NAYLOR AND B KEOGH Explanation j V A Although it seems counterintuitive objects do not need a force to keep them moving Moving objects slow down because of friction If there is no friction then the object will keep on moving in the same direction We take friction for granted and don t really notice its acting In this situation the skateboard slows down because of friction There is no force to keep the skateboard moving except when she pushes herself along with her foot The situation can be modelled by using objects which roll or slide and pushing them to see how far they go The effect of pushing with different amounts of force can be investigated Pushing them on a range of surfaces e g a wooden table a polished floor or a carpet will allow the effect of different amounts of friction to be explored Sliding a piece of ice on a polished surface makes a useful comparison Student Centred Approaches for Science Education Part 2 50 17 Soccer Link with curriculum Grade 8 chapter 2 lesson 3 2010 IT COMES DOWN BECAUSE THERE IS IF I KICK THE BALL HARD ENOUGH IT WILL NO UPWARDS FORCE AFTER YOU HAVE NEVER COME DOWN KICKED IT IT COMES DOWN BECAUSE IT RUNS OUT IT COMES FORCE DOWN BECAUSE GRAVITY PULLS Explanation C A common misconception is tha
33. THE SAME DISTANCE BUT THE BIG TORCH SHINES MORE BRIGHTL Y LIGHTS UP A BIGGER AREA A rtevelc hogesch 5o E Explanation E D It is a common misconception that the distance that light travels depends on the brightness of the light source In fact in the same medium light always travels at the same speed so it will travel the same distance What does vary is the brightness of the light and or the area illuminated A brighter torch can illuminate a bigger area illuminate an area more brightly or both Measuring the speed that light travels is extremely difficult A more useful line of enquiry is to observe the area illuminated and the brightness of the illumination with different light sources Enquiry can also include thought experiments What would happen if Student Centred Approaches for Science Education Part 2 46 13 Mirror box Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 MIRROR BOX CS NAYLOR AND B KEOGH rtevelde hogeschool Lak do Unione Cem IF YOU SHINE A LIGHT INTO A BOX LINED WITH MIRRORS THE LIGHT WILL REFLECT Or KUER You OSEN ROUND THE BOX FOR EVER THE CID THE LIGHT WLL BE ABSORBED BY THE MIRRORS Explanation If light were a material substance like air then light would still be in the box after the lid is shut and be released when the lid was opened However light is not a material substance In fact the light is absorbed by the inner surf
34. TS ON THE OVERHEAD TN PROJECTOR uum Explanation As the prism splits white light into its constituent colours it seems reasonable to assume that the different colours can be recombined to white light Using coloured lights can successfully recreate white light Using overlapping coloured filters or paints is more problematic since they produce their colour by absorbing some of the colours from white light e g red paint will absorb green and blue light but reflect red light so that the paint appears red Adding more paint or more filters therefore subtracts more and more colours from white light The ultimate result is black rather than white A systematic enquiry should produce consistent patterns of observations Can more than one prism be used to separate and then recombine the colours in white light What colours result from different combinations of coloured lights What colours result from different combinations of coloured filters What colours result from different combinations of coloured paints These questions form the basis for an enquiry which can lead to a consistent description of the behaviour of coloured light Student Centred Approaches for Science Education Part 2 45 12 Torches Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 TORCHES TUE BIG TORCH THEY BOTH SHINE Nou SHINES FURTHER THE SAME DISTANCE c A REDE HAN THE LITTLE ONE THEY BOTH SHINE
35. The person moves forward because of a forward frictional force exerted by the floor The frictional force exerted by the floor on the box is much smaller Student Centred Approaches for Science Education Part 2 Example 14 Fluid statics Link with curriculum Physics Grade 7 chapter 4 lesson 3 2009 When a hole is made in the side of a container holding water water flows out and follows a parabolic trajectory What will happen with the water flow if the container is dropped in free fall What do you think A The water flow diminishes B The water stops flowing out the container C The water flows out in a straight line D The water flow curves upward E The water flows out faster Answer B is correct When the container is at rest there is pressure on the walls of the container due to the water The pressure depends on the depth and is equal to p g h with p being the density of water When the container is in free fall both the water and the container have an acceleration of zero not gin the container frame of reference In this frame the pressure of the water on the walls of the container is zero so there is no outward flow Example 15 Archimedes Principle Link with curriculum Physics Grade 10 chapter 1 lesson 4 2009 You can start with a short lecture 7 to 10 minutes emphasizing the concepts and ideas of Archimedes Principle Preferably include a demonstration such as the Cartesian Diver see experiment gu
36. URVED MIRROR I SEE MYSELF BACK TO FRONT I THINK YOU ARE UPSIDE DOWN IT DEPENDS ON HOW FAR AWAY YOU ARE Explanation Although with a convex mirror the image is always the right way up this is not the case with a concave mirror The image in a concave mirror can be the right way up or upside down depending on the curvature of the mirror and how far away the object is The critical factor is the position of the object in relation to the focal point that is the point at which rays of light reflected from the mirror cross If the object is closer to the mirror than the focal point then the image will be upright and magnified If the object is further away from the mirror the image will be upside down and reduced in size Systematic observation of the type of image produced by concave mirrors in different circumstances will produce consistent patterns in the size and orientation of the images The concept can be applied to a range of everyday situations such as car wing mirrors and make up mirrors Student Centred Approaches for Science Education Part 2 44 11 Prism Link with curriculum Grade 9 chapter 5 lesson 4 2011 I CAN MAKE DIFFERENT COLOURS USING I CAN MAKE WHITE A PRISM USING DIFFERENT COLOURED LIGHTS rtevelde ogeschool 2 Va an amp nornos Lem Cet PRISM CS NAYLOR EN B KEOGH A h I CAN MAKE WHITE I CAN MAKE WHITE USING DIFFERENT 225 USING DIFFERENT LL COLOURED FILTERS N COLOURED PAIN
37. a eie eee un dee ee ee tte 129 Example 11 Chemical bonds 0 cc cccesceeeseeeeeseeceeeeeeeaeeeeaeeseeeeesaaeeeeaaeseeeeeseaeessaaesnaaeeeeeeeenaees 130 Example 12 Structure of AtOMS sssssssssssssssseseeeeee ener 130 Example T92FOI665 aditu t ERE ERR ER UR te EL ERE 131 Example TA Fluid statics icnn ertet e tede eer te epe tede ete tene 132 Example 15 Archimedes Principle ccsuetarnonseccann oaa 132 Example 16 Archimedes Principle difficult 133 Example tr Electricity sedes 133 18 ioi eie edi ted nata snes enbanaduantaandechsneasuhiarads 133 Example 19 Phase changges iit tetti tinta iti tede Ein bean Ente Pe ena rarus 134 Example 20 Mechanics oer rete te Pene nd eus Il i a etd e bre nna Eneas 134 Ex mple 21 Mechanlcs x nn ete d e te ee Pen eerie a dtu de Peu ve reagent 134 Example 22 Catching a cold emen nennen nens 135 Example 23 Antibioucs o ae ngo ege OE EI E GE t EE E Ee RERO 135 min elc er sr d cde 136 Annex Constructing your own Concept 138 References re CD 139 fool 139 140 Student Centred Approaches for Science Education Part 2 11 Student Centr
38. ace of the box As the light is absorbed the energy has to end up somewhere so the temperature of the mirrors will increase a tiny bit Given the speed at which light travels opening the box lid carefully to see if any light comes out is impossible Nevertheless in theory it would be possible to shine a light into the box shut the lid and then open it in a completely dark area to show that no light emerges Student Centred Approaches for Science Education Part 2 47 Mechanics 14 Bungee jump Link with curriculum Grade 8 chapter 2 lesson 3 2010 p BUNGEE JUMF f rtevelde hogeschool THE BIG PERSON WILL FALL FASTER THAN THE SMALL PERSON WHEN THEY SUMP I THINK THEY BOTH FALL AT THE SAME I THINK THAT THE BIG PERSON WILL GO DOWN FURTHER THAN THE SMALL ONE Explanation n W A very common misconception is that heavy things fall faster than light things Although the force of gravity is greater on a heavier object a heavier object also needs more force to make it move So in this situation the two people will fall at roughly the same rate Air resistance can make a difference to how objects fall particularly if they have a large surface area but in this situation it is unlikely to be noticeable However the big and presumably heavy person will exert a bigger force on the elastic at the bottom of the fall so the elastic will stretch more The situation can be investigated by students by drop
39. altered Completely evaporating some sweet tea will demonstrate that the sugar is still present in the tea Student Centred Approaches for Science Education Part 2 114 Melting Ice same as Physics Link with curriculum Grade 7 chapter 2 lesson 1 2009 MELTING ICE CS NAYLOR AND B KEOGH rtevelde hogeschool an de ustane THE ICE TAKES UP LESS SPACE AS IT MELTS SO IT MUST GET LIGHTER ICE FLOATS ON WATER SO THE ICE MUST GET HEAVIER AS IT MELTS THE ICE WILL STAY THE SAME WEIGHT WHEN IT MELTS p Explanation E R This concept cartoon illustrates the potential confusion between weight and density The ice is less dense than water which is why it floats on water When the ice melts its weight does not change Ten grams of ice will melt to give ten grams of water However the volume does change when the ice melts Ten grams of water take up less space than the ten grams of ice so the density of the ice is less than the density of the water There is plenty of scope for confusion here The water and ice are exceptional in that almost all other substances get more dense as they solidify The weight of a given amount of ice can be checked before and after melting to see whether or not the weight changes Exploring how density alters with change of temperature is more interesting and can lead into useful application of the idea in terms of why icebergs float or where ice for
40. and teachers tried out the techniques discarded some and changed others and provided suitable examples from the local curriculum This manual consists of 6 chapters Chapter 1 Developing Active Reading and Writing Skills presents techniques to stimulate strategic reading and writing skills with students in science lessons Chapter 2 Developing Science Reasoning Skills presents discussion and argumentation techniques for science topics Chapter 3 Teaching the Scientific Method introduces ways to make students familiar with the various stages in the scientific method Chapter 4 Conceptual Science Teaching focuses on techniques to stimulate conceptual thinking with students Chapter 5 Models and Analogies introduces techniques and examples of models and analogies in Science lessons Chapter 6 Educational Games explains how to integrate educational games in science lessons and gives a range of examples We hope that teacher trainers will try out the methods in this manual We are looking forward to receiving your comments We wish you an inspiring experience and many satisfying science lessons Editorial Committee July 2011 Student Centred Approaches for Science Education Part 2 Manual Development Committee Management Committee H E Im Sethy H E Nath Bunroeun Approval Committee Mr Leang Seng Hak Mr Eng Kimly Mr Eung Ngor Hok Committee of Authors Mr Stefaan Vande Walle Ms Veerle Cnudde Mr Uon
41. art 2 92 58 Acquired Traits Link with curriculum Grade 11 chapter 3 lesson 2 2009 Will physical fitness make a difference in their kids If we are in great shape our children will be born that way You are crazy Lifting weights doesn t change your genes think that working out and being fit will gradually change their genes so it will affect their kids The next generation will benefit from our hard physical work 13 Fisher Anderson e Explanation a Answer D is correct because an individual can t change his her own genes in a certain way through certain activities Mutations certainly occur during an organism s lifetime but they are completely unpredictable and very unlikely to take place in reproductive cells like eggs and sperm Answers A B and C are all related to the discarded Lamarckian idea that traits acquired during the lifetime can be passed to offspring This is important to bring up with students several times because it is a common misconception Student Centred Approaches for Science Education Part 2 93 Annex 3 Concept Cartoons for Earth and Environmental Science Disclaimer The cartoons in this manual are taken from the work of Naylor and Keogh For the Khmer version translated and locally drawn cartoons were used The cartoons are copyright protected and cannot be distributed outside RTTCs without written permission of the copyright holder I
42. best answer is sugar The scientific definition of food is an organic substance containing carbohydrates proteins and or fats that serves both as fuel and as building material for an organism Nutrients are organic or inorganic substances that organisms need in order to carry out life processes Examples include water vitamins and salt However nutrients are not a source of energy nor are they used as the building material that primarily makes up the body Plants can make their own food from water and carbon dioxide using the energy from the Sun photosynthesis Example number 8 about the nervous system is the result of an open question used by a teacher during class He noticed that students associate the working of the brain only with deliberate actions and not with unconscious actions such as sleeping or coughing An example for Earth and environmental science A day on Saturn takes about 10 earth hours How would you explain this Possible answers include Saturn is less dense than Earth Saturn is much farther from the Sun than Earth Saturn rotates more rapidly than Earth and Saturn s orbit has greater eccentricity than Earth s The correct answer is the third one The length of a day is only determined by the duration of one rotation around its axis An example for Physics Imagine students throwing a ball up Ask them to draw force vectors on the ball when it is thrown upwards when it reaches its highest point and when it
43. c e There are shadows at night but you cannot see them Pupils often have this idea because they see shadows as real physical objects These objects will become visible with additional light just like any other object Student Centred Approaches for Science Education Part 2 37 e There are no shadows at night Penumbra area of Umbra partial eclipse area of total eclipse Source Wikipedia Shadows are associated with the absence of light at a particular place If there is no light there is no shadow e Everything is shadow at night A picture of the Earth and Sun system sheds a different view on the night There is no light at the night side of the Earth because that Earth side lies in the shadow region of the Earth Sun system When you approach the night this way the night can be seen as one big shadow Most people do not have this feeling because they see shadows as separate entities e Shadows look darker at night When there is a light source during the night e g Moonlight there are shadows Close observation shows that those shadows look darker than during the day time During the day there is more indirect light light reflected on different objects and light scattered by the atmosphere reaching the shadow region So indeed at night the shadows are darker Student Centred Approaches for Science Education Part 2 5 Two trees Link with curriculum Grade 9 chapter 5 les
44. ce Education the ConCISE project Stuart Naylor amp Brenda Keogh Millgate House Publishers Disclaimer The cartoons in this manual were developed by Arteveldehogeschool based on the work from Naylor and Keogh For the Khmer version translated and locally drawn cartoons were used The cartoons are copyright protected and cannot be distributed outside RTTCs without written permission of the copyright holder SA Introduction Nua In each cartoon the scientific correct viewpoint and possible misconceptions are described We suggest ideas for scientific investigations and experiments to clarify the concept The physics cartoons are divided according to main themes in the curriculum optics heat fluids mechanics and electricity Student Centred Approaches for Science Education Part 2 33 Optics 1 The White Cat Link with curriculum Grade 10 chapter 4 lesson 1 2009 WHITE CAT S NAYLOR AND B KEOGH I WILL BE ABLE TO SEE THE WHITE CAT IN THIS DARK ROOM YOU WLL ONLY BE ABLE TO SEE ITS EYES THEY SHINE IN THE DARK YOU WON T SEE ANYTHING UNLESS YOU TURN ON A LIGHT Explanation A common misconception is that a cat s eyes glow in the dark and that we can see white objects in the dark Of course without any light we will not see either the eyes or the cat The cat s eyes and white fur are both reflective surfaces When light is present they reflect it and we can see them clearly In absence of
45. ceptions without input from the students The following information sources are available e Vote results Answer categories that are never chosen should be modified or deleted Student Centred Approaches for Science Education Part 2 136 e Peer discussions may reveal misconceptions e Regularly occurring wrong answers on exams may be used in a concept test e lot of concept tests have been published on internet They are good starting points but always use the information sources listed above to adapt the tests to reflect the misconceptions in your classes Some internet links are listed in annex e End of chapter questions in many textbooks How to interpret the results of Concept tests You can use the results of Concept tests to evaluate your own teaching process For example after low scores on a concept test on Newton s Law you may decide to spend more time on this topic the next year doing an extra experiment or more exercises Student Centred Approaches for Science Education Part 2 137 Annex Constructing your own Concept test You can organize a class discussion such as a brainstorming session to generate many alternative answers For example ask your students to list three items that they think are food for plants Typical answers may include sunlight sugar carbon dioxide minerals fertilizer soil water oxygen vitamins Combine the 5 or 6 most occurring answers to a Concept test The
46. chapter 3 lesson 2 2010 Why do so many scientists study yeast cells to understand human genetics The genes in yeast cells Look I ve work in almost the same made a great Y way as human genes y discovery about east genes are we can leam a lot east have yeast cells identical to human DNA like us but genes the genes don t work the same way Fisher Anderson Explanation A ax Character B says that the genes work in almost the same way which is accurate Although yeast cells are members of the kingdom Fungi and are single celled organisms they are eukaryotic cells that function very similar to the way single human cells function The building blocks for DNA are the same and the processes of transcription and translation are nearly identical although they produce different proteins Because of these similarities scientists can easily run experiments with millions of yeast cells in a very short amount of time Answer A is wrong because if yeast genes were identical to human genes yeast cells would not be yeast cells they would be human However there are many genes related to basic cellular processes such as cellular respiration that are VERY similar Answer C is false because the genes do work in the same way This is important because students may hear about genetic discoveries made using yeast cells and may dismiss them as not being relevant to humans Student Centred Approaches for Science Education P
47. creases exponentially in the higher layers of the atmosphere Predicting what would happen if each of the statements were correct could be an interesting thought experiment Student Centred Approaches for Science Education Part 2 105 Earth and Environment 68 Recycling Link with curriculum Grade 9 chapter 3 lesson 1 2011 Ne will run out of trees ve don t recyt paper Paper is b degradable Y 5 n t need to and Keogh e Explanation Materials might be recycled for different reasons Recycling can be useful to re use scarce raw materials to reduce environmental damage in obtaining raw materials to avoid generating bulky or damaging waste products in manufacturing or to minimize energy use In the case of paper the main purpose of recycling is to minimize the amount of energy used in making paper since less energy is required to make new paper from scrap paper than from trees The fact that paper is biodegradable helps to avoid a build up of paper in the environment but recycling is still useful Leaving paper somewhere in the environment will show how biodegradable it is You can discuss the consequences of not recycling any paper such as an increased requirement for land for growing trees suitable for making paper with reasoning techniques such as in the Fishbowl Agreement Circles or Donuts Student Centred Approaches for Science Education Part 2 106 69
48. d other student centred approaches to clarify the concepts Student Centred Approaches for Science Education Part 2 109 Mixtures Compounds and States of Matter 71 Liquids Link with curriculum Grade 7 chapter 1 lesson 1 2009 ay V Explanation This cartoon deals with the nature of liquids Scientifically a liquid is a substance with a fixed volume but a variable shape It will take the shape of a container Although modelling clay can also have its shape altered it will retain its shape until something acts to change it Runny solids such as sand or salt seem to mimic the property of taking on the shape of the container However individual pieces of sand or salt do not change shape like liquids do Each piece is a small solid Experience of a wide range of substances including some which cannot be categorized easily discussion and reflection are necessary for students to develop understanding It will be helpful to differentiate between pure substances which are fairly easily categorized and more complex mixtures Mixtures are more likely to combine the properties of solids liquids or gases This cartoon can be combined with a cards sort activity in which students classify substances according to criteria they discuss Student Centred Approaches for Science Education Part 2 110 72 Scrambled Eggs Link with curriculum Grade 8 chapter 1 lesson 3 2010 amp Grade 8 chapter 2 lesson 1 2010 Sc
49. e ERR aeac 103 Physical Geography itecto tetas eite eol nun eiecit fete teen e petes 104 67 slot 104 Mountains same as PHYSICS nnns 105 Ean and Environment x ied rc HE era OE HARTE EE REDE 106 68 aisle 0 LEE 106 69 Why is a day 24 hours sssssssssseeeeenm eene nere nere nnne 107 70 etatem ic eto 108 Annex 4 Concept Cartoons for Chemistry 109 Introduction 109 Mixtures Compounds and States of nnne 110 71 Ete oito eonim deut ch 110 72 Scrambled Eggs ish tee he eee fid eed 111 73 112 74 seein e de Wen es 113 75 Sweet Tea Dissolving eiiis cnet oh nb n e ERR E b EAR SEX ERE 114 Melting Ice same as Physics sssssssseseeeeeeenee eene 115 Acids and Bases e D TRO ERE ER RE EUR E ean 116 76 Acidic Orange Sias ee itae poatea treiber tego eo 116 Chemical Reactions rti ce e sen adie EEG HUE ROPA SER e HERES ERE 117 7T Rusty Nails metae m oet e Cae ed ae Por eu deed etos Fete Pete de P Eo E 117 78 UENAEIESUA 118 79 s ether enn ae eL M ea da tr 119 80 Burning Candle 5 252 2 aede ded tenis et dedi e
50. e Pd ein dec nod esci E rire Re Ete Ah eu 39 6 The colour of shadOWs tice ioo Ido esee cee ee pte ied 40 T5 Solar eclipse mia eR e a i HE NEP dents 41 8 Moving ShaAdOW etie e deca e esi e dr ee dale ee Re E ee ania 42 9 Shadow of the Sun size eene nnne nennen nnne nnns tnr enne en 43 10 GC rved milTOr ete renda ete eae e et te PE et 44 11 PUSI tier eee rnt pe eite deed Le epe ect eder pi teen D ge tede e 45 12 eed pte a ee de eee dee ode eee 46 13 E EAT 47 MECHANICS in iai i ea iov a Select io 48 14 Bungee Jump eite Einige 48 15 ts 49 16 Skateboard 5 ER a RE E ee ie 50 17 epo EDS 51 18 Space tocket e a s 52 19 Fast plane wins aii A eR 53 20 MOOR TOGK ie eoe ef de ba a e Ho E e edi lb e f indere 54 21 Hot air balloon operit ee e e e E c aee i fa p i ic e be i dee 55 22 Space Walk a e o e oe dei e EA e D eee 56 23 Ski Slope tute e iet t carats har deus Eee E NR T D eR cede 57 Feat icu i a ep ER E ceno SR en cte NE 58 24 Boiling Water m E og ERR SERERE TREE RAS Uude 58 25 Snowman called Ice and cloth in Khmer version 59 26 TOAD Ol ERN 60 27 Windy day DE 61 28 ee e Geese eet Eh e eee e e e 62 29 When water is boiling nennen nennen nn
51. e are Third Party materials that are being used under fair use or with permission The publisher will not be liable on any legal basis including negligence for any loss or damage suffered through the use of Third Party material Student Centred Approaches for Science Education Part 2 Prologue Capacity building and human resource development are one of the crucial angles in the rectangular strategy of the Royal Government of Cambodia Qualitative science education is an important factor in creating a well educated workforce Not only is there a strong need for people with degrees in scientific domains but science education also contributes to developing students into well informed critically and creatively thinking citizens In cooperation with development partners and international organizations the Ministry of Education Youth and Sport MoEYS has developed educational materials to fulfil the needs of teaching and learning The process of material development and capacity building consisted of joint efforts of the technical expertise of both the MoEYS and VVOB educational experts This enabled us to design materials that focus on basic knowledge and teaching methodology for science subjects This manual focuses on the theory and practices of science education and the promotion of problem solving skills reasoning skills reading comprehension creativity and deeper understanding of science The manual also offers solutions to make scienc
52. e discussed Use questions to help students constructing the correct reasoning For the example on shadows questions that can be used are a What happens if we move our hand closer to a light source b Is there still a shadow if you cover the light source completely c Can you think of a situation where the size of the shadow doesn t change d Can you explain why e Howcan the size of a shadow cast by the Sun change Explanation of statements 1 My shadow is biggest when I am close to the screen 2 Your shadow is biggest when you are close to the lamp These two answers are best discussed together because they represent opposite views It s very unlikely that a student will agree with both ideas Let students discuss and make a plan how to check which answer is correct The answer can be found by experimenting and or by using theory and reasoning A short experiment with the light source and hands quickly shows that a shadow is bigger if the object is closer to the light source It can also be explained with the fact that light travels by straight lines and that a light source diverges light in all direction Student Centred Approaches for Science Education Part 2 17 Figure The closer the object to the light source the bigger its shadow Source Wikipedia 3 The shadow is the same no matter where you stand With a light source you can demonstrate that this is not true If you move your hand the size of the shadow
53. e ducks with a slightly different beak or a slightly more efficient metabolism could have a competitive edge and survive Student Centred Approaches for Science Education Part 2 85 51 Reproduction Link to curriculum Grade 12 chapter 6 lesson 1 2010 What determines how many babies creatures have But most creatures No creatures just aren t like mice they keep multiplying whether stop reproducing when think each species there is enough food there are enough has as many babies as it needs Fisher Anderson Explanation Jag Character B is correct since reproduction typically takes place whether there are enough resources or not Obviously not all offspring will survive if there are not enough resources Most organisms have no control over the number of offspring they produce This may come as a surprise to students Student Centred Approaches for Science Education Part 2 86 52 Resistance Link with curriculum Grade 12 chapter 6 lesson 1 2010 The invasion of the ants think that out of all of these It works like this ants there are probably These ants wil die but a couple that can survive the new ones that come That should and reproduce will smell the spray and work since they are will gradually be able to all alike it will kill resist the spray all of them I m going to kill all of these ants with this bug spray Explanation ey Answer B is most accurate du
54. e lessons more connected to students daily lives MoEYS strongly hopes that all teacher trainers will use this manual to teach science in the teacher training centres and thus contribute to improving the quality of science education in Cambodia On behalf of MoEYS would like to express sincere thanks to the team and educational advisors of the Flemish Association for Cooperation Development and Technical Assistance VVOB for their energy motivation and intellectual spirit to develop these useful manuals Phnom Penh March 15 2012 Minister of Education Youth and Sport H E Im Sethy Signature and seal Student Centred Approaches for Science Education Part 2 Preface The manual on Student Centred Approaches SCA in Science Education is compiled in order to support science teacher trainers in their teaching In 6 chapters we present a wide range of tools and techniques to increase the student centred character of science lessons A student centred approach means literally that the student is placed in the centre of the learning process Some characteristics of a student centred approach include Active involvement of the students in the lesson Students learn from each other not only from the teacher Students are more responsible for their own learning Differences among students are taken into account The tools and techniques in this manual were first introduced at RTTC Kandal A team of teacher trainers
55. e same material C Use a ball of the same size made out of a denser material D Use a ball of the same size made out of a lighter material E Add more water to the tank so it is deeper F Add salt to the water G Attach a weight to the ball The best answers are C and G The degree to which a solid object will float when placed in water depends on the density of the material To be further submerged the density of the object must be increased By using a ball of the same size in a denser material the ratio of mass to volume is greater and the object will be further submerged Adding salt to the water makes the object more buoyant because salt increases the density of the water Example 10 Dissolving Link with curriculum Chemistry Grade 8 chapter 3 lesson 3 2010 When stirred a teaspoon of sugar into a glass of warm water the sugar completely dissolved in the water Which statements are true more than one correct answer possible A The sugar melts B The sugar loses mass C The sugar turns into water molecules Student Centred Approaches for Science Education Part 2 129 D The sugar forms a mixture with water E The sugar can be separated from the water F The sugar disappears and no longer exists G The sugar molecules are spread among the water molecules H The sugar breaks down into the individual atoms that make up sugar I The sugar chemically combines with the water to form a new substance The be
56. e shadows look darker than during the day During daytime there is more indirect light light reflected on different objects and light scattered by the atmosphere reaching the shadow region 29 z5 Conclusions E 1 Ideas that seem irrelevant at first may turn out to be logical and worthwhile after all 2 The conclusions we made after the previous concept cartoon are still valid even if we consider the Sun Earth system 3 The darkness of a shadow is influenced by secondary light sources Student Centred Approaches for Science Education Part 2 22 4 3 Experimental Investigation Introduction gt The two previous methodologies have highlighted the value of scientific discussion Stimulating students to discuss their opinions creates a strong learning environment For some cartoons it is possible to combine scientific discussion with experimentation Scientific discussion leads to the formulation of a research hypothesis which can then be tested experimentally After initial discussion students do the experiment in groups or the teacher does the experiment as a demonstration THE SHADOW 15 TWICE AS DARK WHERE THE SHADOWS OVERLAP THE SHADOW IS JUST r SAME WHERE THE SHADOWS OVERLAP THE SHADOM IS A BIT DARKER BUT NOT TWICE AS DARK Objectives To detect student teachers misconceptions For the concept of shadow students may think that you can add the darkness of two overlapping shadows Stud
57. e to variation in large populations of insects The few ants that may be able to survive the spray will reproduce to make the next generation Answer A denies variation in the population Answer C reflects a very common misconception that individual insects develop resistance to chemicals when the chemicals are applied It would be worth mentioning to students that typically this type of resistance takes a long time to become a problem but this explains why current malaria treatments that were very effective several years ago are no longer working well in some areas Student Centred Approaches for Science Education Part 2 87 53 Pond Life Link with curriculum Grade 10 chapter 1 lesson 6 2008 The fish will use There is oxygen in up the oxygen the food that they and die and B Keoat S Naylor e Explanation i Unless conditions are very unusual it is unlikely that the fish will use up all the oxygen and die Fish have been living in ponds and lakes for many years without using up all the oxygen and dying so they must be getting oxygen from somewhere else The fish get more oxygen from the air as it dissolves in the water They can also obtain oxygen from the plants which release it into the water in the process of photosynthesis This is not a situation which can be investigated practically There are useful parallels in how aquatic plants obtain carbon dioxide for photosynthesis from carbon dioxide gas dis
58. e which answer categories were chosen by the students and whether you can improve your instruction Delete or modify categories that were not chosen by the students Student Centred Approaches for Science Education Part 2 123 Give brief Discuss with Majority Give detailed lt neighbors lt incorrect gt explanation Y optional hint Majority correct Source Mazur 1997 5 When to use this technique Students require minimal experience with the technique though regular use in class helps them become comfortable with the method Apply the technique during stage 3 of your lessons Concept tests should not be graded in order to ensure honest answers and to encourage everyone to participate freely Demonstrations can be used in combination with a Concept test They can be used to introduce a question whose answer forces students to think about what they have observed A demonstration can also be used to answer a Concept test Because of the test students will pay closer attention to the demonstration They want to see whether their answer was correct Concept tests can also be constructed around animations or video clips A certain degree of flexibility is required when applying Concept tests Depending on the outcomes you may need to include additional instruction such as experiments or exercises During a typical lesson you may introduce one Concept test up to about five Student Centred Approaches for Science Ed
59. e without the nail shows that the magnetic effect is due to the electric current and not because of the presence of the nail Student Centred Approaches for Science Education Part 2 73 Annex 2 Concept Cartoons for Biology Disclaimer The cartoons in this manual have been developed by Arteveldehogeschool based on the work from Naylor and Keogh For the Khmer version translated and locally drawn cartoons were used The cartoons are copyright protected and cannot be distributed outside RTTCs without written permission of the copyright holder Introduction Na SS N In each cartoon the scientifically correct viewpoint and possible misconceptions of the students are described We also suggest experiments and other student centred approaches to teach the concept Student Centred Approaches for Science Education Part 2 74 Plants 40 The Growth Direction of Plants Link to curriculum Grade 10 chapter 1 lesson 5 2008 It doesn t matter which way up they are Upside Down Seeds Alex Danny and Kim are in the garden They are growing some Jn seeds They want to make sure that the seeds grow properly Put them in the right But if they re upside down the plants will grow upside down Source Brenda Keogh and Stuart Naylor A A Explanation Did you ever wonder why plants in nature always seem to grow the right way up even though their seeds have landed o
60. ed Approaches for Science Education Part 2 Chapter 4 Conceptual Science Teaching Chapter 4 Conceptual Science Teaching Concept Cartoons 1 Introduction fs VA R NI Nu 4 About this manual This chapter introduces concept cartoons and concept tests as tools for teacher trainers who want to make their lessons more student centred Both tools involve individual thinking and group discussion and stimulate students to express their ideas on scientific concepts to each other Both tools focus on understanding and applying scientific knowledge in new contexts By creating new concepts cartoons and tests students learn higher order thinking skills and stimulate their creativity and lateral thinking Both tools can be used in a variety of ways depending on lesson objectives students prior knowledge and available time We include sample concept cartoons and concept tests for a variety of topics and different ways to integrate them in the lesson plan Laminated A4 colour copies of all cartoons complement this manual Also digital versions of the cartoons are available for download on the krou org website The manual is based on the work of Naylor and Keogh and Arteveldehogeschool in Ghent Belgium Cartoons were adapted to the Cambodian context where necessary and redrawn through the cooperation between VVOB and Invent Design amp Printing Student misconceptions An important concept when using concept car
61. ed in conjunction with worksheets investigations computer animations and film clips The Concept test can be written on the whiteboard or a large sheet of paper You can also write the question on a sheet of paper and have it copied for group work Laminated sheets can be used for many years You can distribute laminated voting cards to the students This gives you a quick overview of the opinions that are present with the students Student Centred Approaches for Science Education Part 2 122 4 How to use Concept tests Before the lesson identify the key concepts of the lesson Divide your lesson in moments of instruction this can include other student centred approaches and the presentation of a concept test Preparing good Concept tests requires considerable effort However once you have a good set of questions you will need less preparation time since part of the lesson time is taken up by the student discussions During the lesson you present one or more questions along with several possible answers You may specify whether only one or several answers are correct The students get one minute to think about each Concept test and then vote with their voting cards or a show of hands The outcome of the vote determines the subsequent actions by the teacher If most students more than 90 know the correct answer you can quickly affirm why it is correct and continue with the lesson An alternative is to let one student explain t
62. efore the thickness of the filament in the lamp The situation can be investigated by setting up a simple circuit in which thinner or thicker wires connect the battery to the lamp With very thin wires it should be possible to notice that the current flow is reduced and the lamp is dimmer though thicker wires do not normally make any difference This cartoon is a useful introduction to the concept of resistance and to how current flow in a circuit is controlled Student Centred Approaches for Science Education Part 2 71 38 Longer wires Link with curriculum Grade 7 chapter 3 lesson 4 2009 LONGER WIRES S NAYLOR AND B KEOGH A rtevelde IF YOU HAVE LONGER WIRES hogeschool GOING TO THE LAMP WIRES GOING TO THE LAMP IT WILL BE BRIGHTER IT DOESN T MAKE ANY DIFFERENCE TO THE LAMP Explanation g E Many students think that with longer wires the electricity will take longer to get round the circuit and the light will be dimmer However using longer wires in a circuit does not make the lamp shine noticeably more brightly or dimly The electricity flows in all parts of the circuit at the same time so having longer wires does not make any difference to the flow of electric current The limiting factor in determining the flow of electric current is the thickness of the filament in the lamp The situation can be investigated by setting up a simple circuit in which longer or shorter wires connect the battery to the la
63. en the Moon is directly aligned with the Sun and the Earth Because the Moon is blocking the light of the Sun it causes a shadow to fall on the Earth Use a model or a poster to explain how a solar eclipse works Example 4 Water Cycle Evaporation Link curriculum Earth and environmental science Grade 9 chapter 2 lesson 1 Link curriculum Physics Grade 7 chapter 2 lessons 1 2011 Grade 10 chapter 2 lesson 3 2009 After you washed your trousers you hang it outside to dry A few hours later your trousers are dry Which answer best describes what has happened to the water in the trousers a few hours later A It soaked into the ground B It disappeared and no longer exists C It is in the air in invisible form D It moved up to the clouds E It chemically changed into a new substance F It broke down into atoms of hydrogen and oxygen Student Centred Approaches for Science Education Part 2 126 The best response is C The invisible form is called water vapour Contrary to many water cycle diagrams water does not immediately go up to the clouds Water on the outside of a cold glass of water confirms us that water exists in the air around us The principle of conservation of matter refutes answer B The substances liquid water and water vapour are still chemically the same They do not change into a new substance or break down into hydrogen or oxygen atoms Example 5 Origin of Oil Link with curriculum Earth and environm
64. ense The filter stops all the frequencies of the light except for the frequencies of orange light thus creating a shadow for the frequencies of non orange light So shadows can be light and light can be a shadow This manual describes for every cartoon in detail how you can use it It contains objectives material needed activities and expected results The methods that were applied for the concept shadows will inspire you to apply them to other cartoons see the link to curriculum Student Centred Approaches for Science Education Part 2 28 5 When to use concept cartoons You can use them at the start of a topic to provide a stimulus for discussion and raise questions about what needs to be done to find out more This can help students to identify starting points for further inquiry and learning They can also be used near the end of instruction on a topic Then the emphasis will lie more on reviewing and consolidating the learning Introducing a cartoon will offer an opportunity for students to apply what they have learned to a real life situation 6 Examples from the curriculum 6 1 Physics We selected 39 cartoons covering a wide range of topics from the curriculum Each cartoon is described in detail in Annex 1 Optic Mechanics Heat Fluids Electricity 1 The white cat 2 Sunglasses 3 Shadow screen 4 Shadows at night 5 Two trees 6 The colour of shadow 7 Solar Eclipse 8 Moving shadow
65. ent teachers learn to design experiments to simulate the situation in the cartoon Student teachers can verify the ideas in the cartoon by experimental investigation and draw correct conclusions Student teachers can apply their conceptual knowledge on shadows for the situation where two shadows overlap Student Centred Approaches for Science Education Part 2 23 Non transparent object the overlapping part is as dark as the other shadows Transparent object the overlapping part is a bit darker Material needed concept cartoon material for experiment for the example on shadows this includes 2 6 light sources flash lights or light bulbs materials that are not transparent tracing paper or mosquito net a projector Ideally there is enough material to let each group execute the experiment Step by step instructions 1 Introduce the topic to the students 2 Give students a short opportunity to think individually about the statements on the cartoon Then ask students which statement they agree with e g by raising hands or with voting cards 3 Let students work together in small groups to investigate the overlap of shadows It is important that they simulate the 2 situations not transparent and transparent Present them with the available material but don t give too many instructions Students should try to design and execute the experiment themselves 4 Groups present their outco
66. ental science Grade 9 chapter 2 lesson 5 2011 Link with curriculum Chemistry Grade 10 chapter 4 lesson 1 2008 Several friends are arguing where oil comes from This is what they said A It comes mostly from giant ferns and tress that lived millions of years ago B It comes mostly from inside ancient rocks that changed into oil after millions of years C It comes from shallow ocean water that turned into oil millions of years ago D It comes from microscopic and other ocean organisms millions of years ago E It comes from ancient mud sand and soil that gradually turned into liquid millions of years ago F It comes from gasoline trapped inside the Earth s crust for millions of years The best answer is D Oil comes from the fossil remains of tiny marine organisms plankton As they died their bodies collected on the seafloor and were gradually buried under layers of sediment The remains of the organisms were gradually chemically transformed over millions of years into oil Coal comes primarily from land vegetation answer A Gasoline is a product of oil and is not found naturally within the Earth like oil Example 6 Photosynthesis Link with curriculum Biology Grade 8 chapter 1 lesson 1 3 2011 Take a look at the trees outside Where did most of the matter that makes up the wood and the leaves of the trees originally come from A Sunlight B Water C Soil D Carbon Dioxide E Oxygen F Minerals Studen
67. entred Approaches for Science Education Part 2 35 3 Shadow screen Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 MY SHADOW IS BIGGEST WHEN AM CLOSE TO THE SCREEN YOUR SHADOW IS BIGGEST WHEN YOU ARE CLOSE TO THE LAMP YOUR SHADOW WILL DISAPPEAR WHEN YOU STAND IN FRONT OF THE LAMP THE SHADOW IS THE SAME NO MATTER WHERE YOU STAND Explanation f The closer the person is to the light source the more light will be blocked The shadow will be biggest when the person stands close to the lamp Rays of light from the lamp spread out in all directions so close to the lamp the light rays are diverging If the Sun is used as a light source the rays of light are parallel and the distance from the screen makes no difference to the size of the shadow The situation can be modelled using a range of objects or shadow puppets cut out from cardboard Drawing simple diagrams of what is happening to the light and shadow will help to reinforce the idea that light travels in straight lines Student Centred Approaches for Science Education Part 2 36 4 Shadows at night Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 THERE ARE NO THERE ARE SHADOWS AT NIGHT SHADOWS AT NIGHT BUT YOU CAN NOT SEE THEM EVERYTHING IS SHADOW AT NIGHT SHADOWS LOOK DARKER AT NIGHT Explanation 7 Let s assume that we have a dark night clouded sky no other light sources Every view has its own logi
68. epartment Mr Chan Sopheap Officer Department of Curriculum Development Mrs Ean Sarin Officer General Secondary Education Department Technical Advisor Mr Chea Phon Vice director Teacher Training Department Translator Mr Keo Mono Technical Advisor Facilitator Science RTTC Student Centred Approaches for Science Education Part 2 Table of contents ProlOQue pr 3 Preface xen neus 4 Manual Development senes innen nnns 5 Management Committee sssesssssssssssssssseseeee eee 5 Approval Committee as tente eee dt eee eec bee ab re e ee edet edd tH e av tns 5 Committee of AUthors ii o deo eee eres ee deve adc eee do eine ded ee edere 5 Editorial Committee reor ieee hve ee doce e e dte edere ec ee ea ritu 6 Technical Advis a itin e b E E EE e E OE RR RR ES 6 ALANIS ALO P P TET 6 Table ofcontetnts omi tire tege boe eet eng o e A eat Get ng ELE e es 7 Chapter 4 Conceptual Science Teaching sssssssssssssssseee entere enne nnne nen 13 Goncept Cartoons eite EH RERUM HE ec eu elc tret eee ota ts 13 te Introduction im ege com e ge Pede deo i Pages die ah 13 e ODJectiVeS su iere eie E ERR RET eee ET T 14 3 Materials et i eue 15 A Methods us De de e nbi ed Det bt e bete beoe dr Dd ec eet 15 4 1 Class Discussion ir AR eed d
69. er education for development With the support of Ay s the government of Flanders 3 N
70. es or In the Fishbowl see chapter on Reasoning Skills Students take side with a cartoon character and justify why their view is correct Creating a concept cartoon can be presented as a challenging activity at the end of an instruction unit Student teachers try to design the most imaginative concept cartoon 8 Important tips A Vad Val A Concept cartoons do not necessarily have a single right answer In many cases the only reasonable conclusion involves It depends on statements Even apparently simple situations can have a number of complicating factors when they are examined more closely Often like in real Science scientific problems don t have a single right answer It is an important goal for student teachers to obtain this insight Many teachers have problems with this method of teaching science Their criticism is that the situations in the cartoons should be specified more clearly so that there is only one right answer It is an important objective of concept cartoons that students learn to express the ideas in the cartoon It is important to let student teachers argue and discuss about science rather than quickly giving the correct answers Therefore it is very important to know what possible answers student teachers may give in order to anticipate in a good way Student Centred Approaches for Science Education Part 2 32 Annex 1 Concept Cartoons for Physics Source Concept Cartoons In Scien
71. ey topic in a lesson They stimulate problem solving skills reasoning skills and argumentation skills This manual is based on the work of Prof Eric Mazur a physics professor from Harvard University in the USA Why Concept tests Much research has shown that traditional instruction fails to challenge students to construct a correct conceptual framework on a topic Often misconceptions are not changed during traditional lecture formats Formulas are memorized and problem solving strategies drilled but students fail to answer very simple conceptual questions about the topic which indicates that students have merely memorized and haven t acquired a higher level of understanding as described in Bloom s taxonomy Why Peer Instruction Peer instruction is a student centred approach to introduce Concept tests in the class After a first vote students discuss the question in small groups sometimes referred to as Ask Your Neighbour There are several reasons for this 1 Because students are very aware of the difficulties involved in grasping a concept they are often more effective at explaining an idea than teachers are 2 Because it provides students with the opportunity to think critically through the arguments that are being developed 3 Students who can explain a concept will better understand and retain it 4 Students are often more motivated to learn from each other 5 Students enhance teamwork and communication skills
72. falls downward You may discover that many students confuse force with momentum and draw two force vectors one up and one down In reality only gravity is acting on the ball as soon as it is thrown away If you get multiple answers on this question on a test you may construct a Concept test or even a concept cartoon out of it Student Centred Approaches for Science Education Part 2 138 References Books Angelo T A amp Cross K P 1993 Classroom Assessment Techniques Jossey Bass Wiley amp Sons San Francisco California USA Churchill E R et al 1997 365 Simple Science Experiments with Everyday Materials Black Dog amp Leventhal Publishers New York Driver R et al 1994 Making Sense of Secondary Science Research into Children s Ideas Routledge Harrison A G and Coll R K 2007 Using analogies in middle and secondary science classrooms The FAR Guide Sage Harrison A G and Treagust D F 1993 Teaching with Analogies A Case Study in Grade 10 Optics Journal Of Research In Science Teaching Vol 30 No 10 pp 1291 1307 A Herr N 2008 The Sourcebook for Teaching Science Jossey Bass Wiley amp Sons San Francisco California USA Keeley P 2008 Science Formative Assessment NSTA Press Corwin Press Thousand Oaks California USA Keeley P et al 2005 Uncovering Student Ideas in Science 25 Formative Assessment Probes Vol 1 NSTA Press Keeley P et al 2007
73. ference across bulbs B and C in series is equal to the potential differences across bulb A Since the power dissipated in a resistor of resistance R is V2 R where V is the potential difference across the resistor the power dissipated by the series combination is one half the power dissipated by resistor bulb A Example 18 Momentum Link with curriculum Physics Grade 11 chapter 1 lesson 4 2009 Suppose rain falls vertically into an open cart rolling along a straight horizontal track with negligible friction As a result of water accumulating in the cart its speed A Increases B Does not change C Decreases Answer 3 is correct The water because it falls vertically does not change the cart s horizontal momentum The mass of the cart increases however and so its speed decreases Student Centred Approaches for Science Education Part 2 133 Example 19 Phase changes Link with curriculum Physics Grade 7 chapter 2 lesson 1 2009 Put five ice cubes in a glass After 20 minutes most of the ice had melted to form ice water There were still some small pieces of ice floating in the water Measure the temperature of ice water Then add five more ice cubes Three minutes later measure the temperature A The temperature of the ice water increased B The temperature of the ice water decreased C The temperature of the ice water stayed the same The best answer is C The temperature of the ice water stayed the same
74. h we look different on the outside we are all the same on the inside Answer B is correct in that our environment does influence how we end up but genes definitely are involved Student Centred Approaches for Science Education Part 2 90 56 Timeline of natural selection Link with curriculum Grade 12 chapter 6 lesson 1 2010 How long does natural selection take to happen millions hundreds several several several of years of years years months days how fast the species akee miis ot seen in a single think that reproduces but it generation if the habitat even if the environment still takes at least E changes dramatically changes the species hundreds of years do not Explanation f Character says that natural selection could take place a single generation if there were dramatic changes such as severe drought or an epidemic of a fatal disease This is not correct since you need various generations to create an evolutionary pattern Answers A and B are correct in that natural selection certainly does occur over long periods of time but that much time is not always needed As character A states it does depend on the pace of reproduction and can even take place within the course of a few weeks or months as for bacteria Answer D is denying that species change Student Centred Approaches for Science Education Part 2 91 Genetics 57 Yeast cells versus human cells Link with curriculum Grade 12
75. he correct answer If most students have not chosen the correct answer students are given two minutes to try to reach consensus with their neighbour s Afterwards ask the question a second time to assess evolution in class understanding If possible write down the approximate percentages of students who answer each possibility It provides valuable information to improve and monitor your teaching The time for peer instruction usually increases both the percentage of correct answers and students confidence how sure they are of their answer The greatest improvement is usually observed when about half the students are correct initially Then there can be gains of 40 per cent However sometimes students may converge in an incorrect answer which identifies a shared misunderstanding If after the second vote you are not satisfied with the students performance you need to slow the pace and provide additional instruction If possible evaluate students understanding again with a second Concept test When the results show an understanding of the concept you can briefly explain the question and move on to the next topic During argumentation periods circulate around the class and listen to the conversations Make a mental note when students make a wrong argument but don t interfere in the discussion Wrong arguments may provide you inspiration for future Concept tests After the lesson review the questions and the vote results Analys
76. i lb f 83 49 Adaptation TTE 84 50 zie ch a a ede e E e eet 85 51 Heprodu ctlori ciiin e deri pe i Be p a LE E RE REC tia 86 52 EET 87 53 Pond LM re satire 88 54 MA REEL 89 55 2 E ERE 90 56 Timeline of natural selection 91 Genetics 0k eee ia ian aa t e re ene ee ree Gen ete aa i dde 92 57 Yeast cells versus human cells 92 58 Acquired Talls ebsos uenisse eee ned ate en eee ea tee te etude eee AE 93 Annex 3 Concept Cartoons for Earth and Environmental 94 INtrODUCTIONS EE 94 The Solar System and the Universe 95 59 Is 1 a tete e t Epson ea ai RD ette io eed 95 60 i UR LU COME DANI MOL M DUDEN IM LI pn 96 61 Why does the Moon 5 a a 97 62 Daytime MOON tee det cede ed isa re e tee bd ders 98 Student Centred Approaches for Science Education Part 2 63 Moon SHAPES A 99 64 Dark Side of the Moor steppes sided ene 100 65 Moon Boot C 101 Spacewalk same as PHYSICS ccceccceceeeeeeeeenseeeeeeeeeeeseneeeesenaeeeesenaeeeeseeaeeeeseneeeenees 102 66 Lunar EClpS x tett
77. ide physics Try to avoid equations at this point Then present the following Concept test Imagine holding two identical bricks under water Brick A is just beneath the surface of the water while brick B is at a greater depth The force needed to hold brick B in place is A larger B the same C smaller than the force required to hold brick A in place The correct answer is B The buoyant force on each brick is equal to the weight of water it displaces and does not depend on the depth Student Centred Approaches for Science Education Part 2 132 Example 16 Archimedes Principle difficult Link with curriculum Physics Grade 10 chapter 1 lesson 4 2009 A boat carrying a large boulder is floating on a lake The boulder is thrown overboard and sinks The water level in the lake with respect to the shore A Rises B Drops C Remains the same When it is inside the boat the boulder displaces its weight in water When it is thrown overboard it only displaces its volume in water so the water level with respect to the shore goes down Example 17 Electricity Link with curriculum Physics Grade 7 chapter 3 lesson 6 2009 The three light bulbs in the circuit all have the same resistance Given that brightness is proportional to power dissipated the brightness of bulbs B and C together compared with the brightness of bulb A is A Twice as much B The same C Half as much Answer C is correct The potential dif
78. il at the surface probably because that is where we see the evidence of boiling In fact the water boils at the bottom of the pan because that is where it is heated and the water turns into bubbles of gaseous water Although water is made up of hydrogen and oxygen separating the hydrogen and oxygen is a more difficult aad dangerous chemical process which does not occur when water boils Sophisticated equipment it is needed to demonstrate that the bubbles are made of gaseous water Student Centred Approaches for Science Education Part 2 63 30 Ice cubes Link with curriculum Grade 10 chapter 2 lesson 3 2009 ICE CUBES S NAYLOR AND B KEOGH THE SMALL ICE CUBE MELTS FIRST BECAUSE IT DOESN T NEED TO BE HEATED MUCH rtevelde hogeschool THE BIG ICE CUBE SRON MELTS FIRST BECAUSE IT HAS A BIGGER SURFACE THEY BOTH MADE OF THE SAME ICE SO THEY WILL MELT AT THE SAME TIME ar y gt We i Explanation The smaller ice cube will melt first Assuming that the two ice cubes have the same temperature the bigger ice cube needs more heat energy to melt it because there is more ice to be melted The ice cubes gain energy from the environment The bigger cube has a larger area and will gain energy more quickly However the smaller cube has a larger area volume ratio so it will melt before the bigger cube The situation can be investigated quite easily using a range of different sized ice cubes and timing how long they take
79. ive Understanding can be further complicated by learning about electric current without clearly separating it from electrical energy The electrical current enables energy to be transferred and although electric current is constant around the circuit the electrical energy is not If an ammeter is available then the electric current can be measured at various points on the circuit to show that it is constant Analogies see the chapter on analogies and models may help students to distinguish between current flow and energy transfer Finding out more about the chemical reactions going on inside the battery is also helpful Student Centred Approaches for Science Education Part 2 70 37 Thicker wires Link with curriculum Grade 7 chapter 3 lesson 4 2009 THICKER WIRES CS NAYLOR AND B KEOGH A TE YOU HAVE THICKER A rtevelde WIRES GOING TO THE LAMP hogeschool IT WILL BE BRIGHTER IF YOU HAVE THINNER WIRES GOING TO THE LAMP IT WILL BE BRIGHTER YA THE THICKNESS OF THE WIRES DOESN T MAKE ANY DIFFERENCE TO THE LAMP ac NN Explanation Many students suppose that with thicker wires there will be more electricity flowing and the lamp will be brighter However using thicker wires in a circuit does not make the lamp shine more brightly The brightness of the lamp depends on the resistance to the flow of electric current round the circuit The limiting factor in determining the flow of electric current is ther
80. ividual adapting Answer D is incorrect because adapting has nothing to do with intelligence Students may benefit from an explicit discussion on the specialized use of the term adapt by biologists In daily language adapt refers to as any type of change over time Students often transfer this use to biology but it is not compatible with the way that biologists use the term We suggest to students that the word acclimatization would be a better term to use for non inheritable changes in behaviour made by an organism during its lifetime for example acclimatization to high temperatures Student Centred Approaches for Science Education Part 2 84 50 Competition Link with curriculum Grade 12 chapter 6 lesson 1 2010 When there is not enough food what happens All of the ducks will work together to find food They cooperatel No some ducks will need to change so that they can eat other Explanation Ducks will always fight for food and the biggest ones always get the most Some ducks will not get enough food and may get sick and weak Answer C is the correct answer and acknowledges that some ducks may starve Answer A is inaccurate because cooperation amongst members of a population is very rare Answer B implies that an individual is capable of changing to meet needs Character D makes the mistake of assuming that it is always the biggest and strongest ducks that will get the most food In reality th
81. lass is not essential for condensation to occur and that water is not leaking out of the glass Comparing the amount of condensation in still air moving air warm air and moist air helps to make the connection with water vapour in the air evident Exploring where and when condensation occurs is a useful way to learn about condensation Student Centred Approaches for Science Education Part 2 113 75 Sweet Tea Dissolving Link with curriculum Grade 8 chapter 3 lesson 3 2010 What will happen to the The sweet tea will be weight if you dissolve lighter than the tea some sugar in the tea and sugar separately x m a 3 gt E z The sweet tea will The sweet tea will be the same weight be heavier than the 15 the tea and tea and sugar sugar separately separately T Explanation a W i A common misconception is that when substances dissolve they just vanish Even though the sugar is invisible when it is dissolved the total weight of the substances in the tea and sugar does not change This is why the tea tastes sweet since the sugar is still present but invisible Weighing the tea and sugar before and after dissolving is straightforward and will indicate clearly whether the weight has altered A lever balance can be used if sensitive scales are not available The balance can be levelled with tea and sugar separately on one side then the sugar is dissolved in the tea and the balance checked to see if it has
82. lved air However it will take longer due to the lower concentration of oxygen Cold conditions will slow down rusting due to the lower concentration of water in cold air Although rust may look like a disease it isn t The presence of other rusty nails does not make rusting more likely You can let students investigate the situation by setting up various combinations of the different factors let them first brainstorm to determine these themselves that might be involved in rusting Removing air completely is the most difficult part of this A layer of oil or paint will keep the air out but it will also prevent moisture getting to the nail Boiling water for a few minutes to remove the air then putting a nail in boiled water in a sealed container can provide water but no air as a comparison Make sure to test one variable at a time and to provide control set ups Student Centred Approaches for Science Education Part 2 117 78 Rusty Nails 2 Link with curriculum Grade 11 chapter 2 lesson 1 2009 When the nals 9 rusty the jar of nails will stay the sar When the nails go rusty the jar of nails val get heavier e Explanation 4 i As nails rust they get heavier This is an important indication that the process which is occurring is a chemical reaction and not just a physical change If the jar does not have an airtight seal then the total weight of the jar and nails will be heavier as the iron nails react with
83. m s acceptable and what further information we need to be sure 6 Combine the different ideas and provide a summary of the initial problem Ask students whether they changed their opinion Explanation of statements Let s assume that we have a dark night clouded sky no other light sources Every view has its own logic No statement is completely right or wrong 1 There are shadows at night but you cannot see them Pupils often have this idea because they see shadows as real physical objects These objects will become visible with additional light just like any other object Student Centred Approaches for Science Education Part 2 21 2 There are no shadows at night Shadows are associated with the absence of light at a particular place If there is no light there is no shadow 3 Everything is shadow at night A scheme of a lunar eclipse shows a different view on the night There is no light in the night portion of the Earth because that portion of the Earth is in the shadow region of the Earth Sun system When you think of the night this way the night can be considered as one big shadow Most people do not share this opinion because they see shadows as separate entities Penumbra area of Umbra partial eclipse arca of total eclipse Source Wikipedia 4 Shadows look darker at night When there is a light source during the night e g the Moonlight there are shadows Close observation shows that thos
84. me common misconceptions shadows are Shadows are real objects When there is no light there can be no shadow To make student teachers aware of the logic behind different knowledge models and of the fact that their validity depends on the circumstances To broaden students conceptual knowledge To let student teachers practice scientific argumentation and listen to alternative viewpoints Student Centred Approaches for Science Education Part 2 20 Material Concept cartoon A3 or A4 print or projected on a screen Optional 2 6 light sources flashlights or light bulbs a projector be a good light source for class discussions Step by step instructions 1 Divide the class in small groups and distribute the concept cartoon 2 Let students think individually with which view they agree approx 2 minutes 3 Encourage discussion and tell groups to seek consensus If they reach consensus very rapidly they must find reasons why students may have another idea Otherwise you can add extra elements such as making distinction between a clouded night and a clear sky night with full Moon approx 10 minutes 4 Ask students some brief feedback to see what range of views is present among the students You can organize a vote e g by raising hands or with voting cards 5 Let groups with different views share their arguments and organize a class discussion Discuss which alternative s see
85. mes to each other 5 Organize a class discussion about the concept shadow Due to the complex situation the previous definition of the concept shadow may have to be reconsidered and broadened Student Centred Approaches for Science Education Part 2 24 Explanation of statements With this concept cartoon we need to distinguish between 2 situations 1 The shadow is twice as dark where the shadows overlap When students choose this statement they consider a shadow as an object If you add two shadows you get a new shadow that is twice as dark They forget that if there is a shadow it just means that there is almost no light in that space Almost no light because there is always some indirect light we need to take into account 2 The shadow is just as dark where the shadows overlap If shadow is defined as the absence of light of the light source it is obvious that you can take away the light from that source only once If it s gone than you can t take any more light from the light source away So the place where two shadows overlap is as dark as the other shadows The experiment makes this clear as long as you overlap the shadows of two objects that are not transparent 3 This shadow is a bit darker but not twice as dark When a student chooses this answer he or she has a more complex situation in mind The situation drawn in the cartoon is one with trees Trees are a little bit transparent depending on
86. mp Normally the length of wire does not make any noticeable difference However there may be some reduction in brightness with very long wires or with reasonable lengths of very thin wires This can be a useful introduction to the concept of resistance and to understanding how current flow round a circuit is controlled Student Centred Approaches for Science Education Part 2 72 39 Electromagnet Link with curriculum Grade 7 chapter 5 lesson 3 ELECTROMAGNET CS NAYLOR AND B KEOGH YOU DON T NEED A NAIL AT ALL THE COIL OF WIRE WORKS ON ITS OWN YOU NEED A STRAIGHT NAIL FOR THE ELECTROMAGNET IT DOESN T WORK IF THE NAIL IS BENT 1 rtevelde J hogeschoo D YOU NEED TO cw amp w USE INSULATED 22 SS WIRE SO THE m NA ELECTRICITY BU E CAN T LEAK OUT YOU NEED TO 2 USE NON 4INS LATED WIRE SO THE ELECTRICITY CAN GET INTO THE NAIL gem Explanation Ac Ye The magnetic effect of electrical current flow is very important in our electronic age Although it can be shown most readily using a nail or some other soft iron object as a magnetic core this is not necessary for the magnetic effect to be present Setting up a circuit like the one shown will allow the various alternatives to be investigated The magnetic effect can be shown with a compass needle or by the degree of attraction shown to objects such as paperclips Exploring the magnetic effect of a coil of wir
87. ms as water is freezing Student Centred Approaches for Science Education Part 2 115 Acids and Bases 76 Acidic Oranges Link with curriculum Grade 9 chapter 3 lesson 2 2011 f Explanation This cartoon discusses the meaning of acidic and whether all acids are poisonous The use of the term in daily life suggests that all acids are poisonous Students often don t make distinction between poisonous and highly corrosive acids such as Sulphuric acid and those that are not such as citric acid in citrus fruits or ethanoic acid in vinegar The term poisonous is itself problematic since virtually all foodstuffs can be damaging in sufficient quantity including essential items such as salt sugar and water An approach for investigation is to start with common foods e g lemons vinegar and to see whether these share the same properties as some acids such as producing bubbles of carbon dioxide gas when mixed with calcium carbonate in chalk or eggshells or changing the colour of an indicator such as red cabbage juice Student Centred Approaches for Science Education Part 2 116 Chemical Reactions 77 Rusty Nails Link with curriculum Grade 11 chapter 2 lesson 1 2009 y gn 1 B Keo e a w Explanation Rusting requires the presence of air and liquid water so wet nails will rust quickly If they are completely submerged rusting will still occur because water contains disso
88. n However the Sun generates light itself while the Moon only reflects light from the Sun Some direct evidence of this can be obtained by close observation of the Moon If the Moon is examined with a telescope or pair of binoculars then the part of the Moon which is in darkness can be seen as well as the part which is reflecting the sunlight This suggests that the Moon is not generating light itself otherwise all of the Moon s surface would be bright Student Centred Approaches for Science Education Part 2 97 62 Daytime Moon Link with curriculum Grade 8 chapter 3 lesson 1 2010 X X Where does the moon qo to Guring the lor and B Keogh fi Explanation A j i i The Moon does not follow the same 24 hour pattern as the Sun The Moon does not rise at the same time each day and its position in the sky changes daily taking slightly more than 29 days to return to the same position in the sky Sometimes the Moon can be seen during the daytime with the Sun and Moon visible in the sky simultaneously The position of the Moon in the sky can be observed every 24 hours and recorded over a period of time The Moon s apparent movement will follow a regular pattern which can be predicted Each month there is a period when the Moon is visible in the sky during the daytime rather than being visible at night Student Centred Approaches for Science Education Part 2 98 63 Moon Shape Link with curriculum Grade 8
89. n the ground in a random manner It doesn t matter which way up the seeds are when they start to grow There are mechanisms called tropisms inside the plant which ensure that the shoots always grow upwards or towards the light and the roots always grow downwards or towards water Seeds can be grown in suitable conditions to find out whether the orientation of the Seeds makes any difference to how they grow It is necessary to provide the conditions that they need for germination to occur air moisture and warmth The seeds can be planted in various orientations including letting them begin to grow and then inverting them Large seeds are easiest to manipulate Student Centred Approaches for Science Education Part 2 75 41 Seeds in the Dark Link with Curriculum Grade 10 chapter 1 lesson 5 2008 Source Brenda Keogh and Stuart Naylor Explanation P p i 4 The fact that green plants need light to grow is common knowledge Therefore many students think that seeds also need light to start growing This is not the case Although a small number of seeds e g lettuce may need some light to break their dormancy most seeds do not require any light If they did need light none of them would grow when buried under the ground The influence of light can be tested with a range of seeds It is necessary to provide the other conditions that they need for germination to occur air moisture and warmth You can vary the amount of light fr
90. nd the Earth This means that it always faces the same way in relation to the Earth and therefore has a face which we never see from Earth Although we call this the dark side for about half of the time it is brightly lit by the Sun We call it the dark side simply because we never see it You can help students to understand this through models and simulations The situation can be modelled with a globe and strong light source and a small white ball to represent the Moon By changing the relative positions of the Moon Earth and Sun it is possible to model how the different sections of the Moon are illuminated and to show that there is no dark side Student Centred Approaches for Science Education Part 2 100 65 Moon Boots Link with curriculum Grade 8 chapter 3 lesson 1 2010 think they are to keep our feet warm think they are to stop us Sinking into the dust think they are just part of our airtight suits think they are to keep us the right way up S Naylor and B Keogh Explanation This cartoon combines ideas about space atmosphere and gravity There are strong similarities between an astronaut s airtight suit and a suit from a deep sea diver Since the deep sea diver has heavy boots to prevent him her floating up to the surface it is easy to assume that in the lower gravity of the Moon the astronauts need heavy boots to avoid floating away from the Moon s surface In fact
91. ne 63 30 teet entend eee beet hele detecte aeter esee baeo d 64 arccmc 65 31 Helium de eae ee 65 32 uiuat E II Uh uS 66 33 Lemonade EPIRI 67 34 MOUFIGITS h a citer diee LAM MIU 68 gei 69 35 SWITCH iss ie o bes res Ced o er beret et e is Hem Eee ae i eese tie tie 69 Student Centred Approaches for Science Education Part 2 36 erm 70 37 AIM CK OF Wires ite eU ee Eee D ee e nec DEN he te Se CE a 71 38 Longer i o Em 72 39 Electtormagnet ione Me dee Ep ad ne mee 73 Annex 2 Concept Cartoons for Biology ssssssssssssseeeeeeeee ener enne senten nennen 74 laiga apla e a AEDES SEEE ER 74 PIAM 75 40 The Growth Direction of Plants esssssssesesesseeeeeee eene nens 75 41 Seeds nithe Dark 2 2 ecu nde Rede ndn ede td perdio den 76 42 Heavy plants sicui tet i rH etie t tole ee atin asians 77 43 RottemADpple s o iive ttti i vea era Etpa cris fete 78 H trrnan body uet EMEN acta eatin cea su Sacha teat cigar 79 44 Headstandixcesvnatsiate pn cot epe tenth Suite tit Area tai 79 45 Ll E 80 46 use 81 Evolution and reproductiori fsck see A a ae ees 82 4T Dorminarnce 53 tS 82 48 Use gt ba a Pe HE ed
92. ntroduction I 2 Nee m N NA For each cartoon we describe the scientifically correct viewpoint and possible misconceptions of the students Moreover we suggest ideas for scientific investigations and experiments to further clarify the concept Student Centred Approaches for Science Education Part 2 94 The Solar System and the Universe 59 Is it dark in space Link with curriculum Grade 7 chapter 1 lesson 2 2009 It must be extremely dark m outer space It wil be bright dunng the daytime and dark at night t will be bright sunlight all the time Naylor and B Keogh I gt tt will be bright near the m and dark further away e 7 Explanation a Ya Although films may create the idea that outer space is completely dark this is not correct Near the Sun or any other star objects will be brightly lit while further away they will not be brightly lit Although empty space appears black like the night sky from Earth this does not necessarily mean that no light is present Day and night are conceptions related to Earth During the day we see light all around us due to the scattering of light in the atmosphere It can be useful to compare this with the situation in space or on the Moon It is not possible to investigate this Thought experiments models and predictions are the most effective means of understanding the situation Student Centred Approaches for Science Education
93. o the cells and the removal of waste products Responses A and D are partially correct Answer E is incorrect since the digestive system doesn t move food and nutrients through different parts of the body That is the function of the circulatory system Example 8 The Nervous System Link with curriculum Biology Grade 9 chapter 2 lesson 1 3 2011 A group of students is discussing the role of the brain in various actions Here is what they said A The brain is necessary for mental actions such as thinking but not for physical actions such as playing sport Student Centred Approaches for Science Education Part 2 128 B The brain is necessary for both physical and mental actions but we don t use it when we are sleeping C We use the brain for all sorts of behaviour Even when asleep our brain is working Answer C is correct Answers A and B correspond to popular misconceptions with students that the brain is only used for certain actions but not for unconscious actions such as coughing sleeping or blinking Example 9 Floating Link with curriculum Physics Grade 10 chapter 1 lesson 4 2009 A student puts a solid ball in a tank of water As shown by the ball on the left it floated halfway above and halfway below the water level What can he do to make a ball float like the ball on the right Several correct answers possible A Use a larger ball made out of the same material B Use a smaller ball made out of th
94. odd 120 Concept Tests amp Peer Teaching rennen nnne 121 1 Introduction What are Concept Tests sssssssssssssssseeeeeeeeeeee nennen nennen nennen 121 Pec M S 122 3 Materialirieeded i eet ee bre eoi ebbe ed 122 4 How to use Concept tests ssssssssssssssssssseeeeene enne nennen nennen 123 5 When to se this technique tote c eta oc tate tec t o e edant 124 6 Exampl8S eH RERO TERR D LAUR GR TED DELE EAR tt 125 Example 1 Why is it dark at nennen 125 Student Centred Approaches for Science Education Part 2 Example 2 Seasons On 2 125 3 501 7 ease nae casks oh teens abe aie Pee eek tee 126 Example 4 Water Cycle Evaporation 126 Example 5 Origin of Oil 127 Example 6 Photosynthesis 127 Example 7 Digestive nnne inn nennen 128 Example 8 The Nervous System ssssssssssssseseseeennee nennen entere senten nnne ns 128 Example 9 Floating ettet be te pete b e i It etu e Pede bee dt ete 129 Example 10 DISSOIVING 5 3 1 ee ee SG dete
95. om dark to bright light Student Centred Approaches for Science Education Part 2 76 42 Heavy plants Link with curriculum Grade 7 chapter 2 lesson 2 2009 Its extra weight comes think it gets bigger but not heavie in through the roots a Source Brenda Keogh and Stuart Naylor Explanation e 1 misconception is that plants feed on soil through their roots in the same way that animals take in food through their mouths This is not correct Although it seems unlikely that air and water turn into new cells in the plant this is what happens in the process of photosynthesis where carbon dioxide from the air and water from the soil produce glucose with the aid of light energy The various factors can be separated to some extent to show that the soil is not necessary for plant growth though small quantities of minerals from the soil are necessary Weighing the soil before and after a period of plant growth will also demonstrate that soil is not taken up through the roots Student Centred Approaches for Science Education Part 2 77 43 Rotten Apple Link with curriculum Grade 10 chapter 1 lesson 2 2008 The apple rots quickly if the soil i moist It rots quickly if the weather i3 cold m z wu It rots quickly if It rots quickly if the z microbes feed on it soi is acidic E amr i Explanation a T Y misconception is that rotting i
96. on can be investigated by measuring the time taken for a set amount of water to drain through different types of soil The grains of soil can be observed with a microscope so drainage can be related to grain size The soils will retain different amounts of water so investigating drainage through wet or dry soils is a useful extension The influence of other factors on drainage such as the amount of organic matter and vegetation can also be investigated Student Centred Approaches for Science Education Part 2 104 Mountains same as Physics Link with curriculum Grade 11 chapter 3 lesson 1 2011 IT S HARD TO BREATHE UP HERE BECAUSE THERE AREN T MANY AIR PARTICLES I THINK THE AIR PARTICLES ARE SMALLER BECAUSE IT IS SO COLD THE COLD MAKES IT HARDER TO BREATHE IN I THINK THE AIR PARTICLES ARE HEAVY SO THEY FALL DOWN THE MOUNTAIN Explanation The issue here is the nature of air particles and where they are The air particles do not change depending on temperature or altitude but there are fewer air particles at higher altitudes Although individual air particles are moving around randomly at high speeds they are still attracted to the Earth by the force of gravity so there will be more at the bottom of the mountain than the top This is why the Earth s atmosphere is only present in a relatively narrow band around the Earth s surface The air density is highest in the troposphere and de
97. onstant Measuring the change in position of the shadow cast by a stick during the daytime will give direct evidence about the rate of movement Using a globe and light source to explore the movement of a shadow is a useful aid to understanding how the shadow forms and why it moves Student Centred Approaches for Science Education Part 2 42 9 Shadow of the Sun size Link to curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 CO DE POORTER BASED ON S NAYLOR AND B KEOGH THE SHADOW IS ALWAYS SHADOW OF THE SUN AS BIG AS THE STICK THE SHADOW OF THE A LN _ STICK WILL ALWAYS Q9 Ga SOMETIMES THE BE BIGGER THAN E dH SHADOW IS SMALLER THE STICK X THEN THE STICK laavaa hogeschool Explanation P The situation can be investigated directly by recording the position of the Sun in the sky or the length of the shadow formed by a vertical stick see also the summer solstice activity in the earth science activity guide This can be carried out at different times of day and at different times of year to show how the position of the Sun in the sky seems to vary The length of the shadow varies according to the position of the Sun in the sky When the Sun is high in the sky the length of the shadow of the stick will be smaller than the stick Student Centred Approaches for Science Education Part 2 43 10 Curved mirror Link with curriculum Grade 9 chapter 5 lesson 4 2011 IN A C
98. our bodies it allows more water to evaporate cooling the skin as it does so The wind also blows away the layer of warm air surrounding our bodies As this warm air is replaced by colder air we lose energy by warming this new layer of air If a container is filled with hot water it will cool as it loses energy to the environment The cooling effect of the wind can be seen if a fan blows a stream of air around the container preferably with the can wrapped in moist tissue paper to show the importance of evaporation The effect of trapping a layer of air around the container can be investigated by wrapping an insulator such as wool or bubble wrap around the container and comparing the rate of cooling This concept can also be explored with the situation of a fan providing cooling during hot days see cartoon in Khmer version Student Centred Approaches for Science Education Part 2 61 28 Melting ice Link with curriculum Grade 10 chapter 2 lesson 3 2009 MELTING ICE CS NAYLOR AND B KEOGH rtevelde hogeschool La an de Amonen inte THE ICE TAKES UP LESS SPACE AS IT MELTS SO IT MUST GET LIGHTER ICE FLOATS ON WATER SO THE ICE MUST GET HEAVIER AS IT MELTS THE ICE WILL STAY THE SAME WEIGHT WHEN IT MELTS Explanation er A This concept cartoon illustrates the potential confusion between weight and density Ice is less dense than water which is why it floats on water When the ice melts its
99. ping a range of objects to see which hits the ground first Factors such as weight surface area and shape can each be investigated Keeping the other factors constant while varying the weight shows that weight makes no difference and emphasises the effect of shape and surface area on the rate of falling see next cartoon Student Centred Approaches for Science Education Part 2 48 15 Falling Link with curriculum Grade 8 chapter 2 lesson 3 2010 E _ PAPER FALLS SLOWLY BECAUSE IT CATCHES THE AIR SLOWLY BECAUSE IT ISLIGHT JJ THE PAPER CLIP FALLS SLOWLY BECAUSE IT IS SMALL Explanation This cartoon is related with the previous concept cartoon on bungee jumpers The weight and the size do not have any direct impact on the rate of falling The feather and paper fall slowly because of their relatively large surface areas which create a lot of air resistance as they fall Investigations could include finding out how to make the paper fall faster such as screwing it up or folding it Similarly the effect of modifying the vane or dropping the feather in different ways can be explored Showing video footage of the first lunar astronauts dropping a hammer and a feather on the Moon where there is no atmosphere will be useful Student Centred Approaches for Science Education Part 2 49 16 Skateboard Link with curriculum Grade 8 chapter 2 lesson 2 2010 THERE MUST BE A FORCE THA
100. r Eclipse Link with curriculum Grade 8 chapter 3 lesson 3 2010 ECLIPS OF THE MOON 5 DE POORTER I THINK A MOON ECLIPS OCCURS WHEN THE SHADOW OF THE MOON FALLS ON THE EARTH NO IT HAPPENS WHEN THE MOON IS IN FRONT OF THE EARTH THE SHADOW OF THE EARTH FALLS ON THE MOON Explanation d E An eclipse of the Moon occurs when the shadow of the Earth falls on the Moon so that the Moon can no longer reflect light from the Sun You can help students to understand this concept through models and simulations using a globe and strong light source and a small ball to represent the Moon Compare the situation of a lunar eclipse with that of a solar eclipse Challenge students with the question why we don t have a lunar eclipse every month Student Centred Approaches for Science Education Part 2 103 Physical Geography 67 Soil types Link with curriculum Grade 9 chapter 1 lesson 1 2011 amp Grade 11 chapter 2 lesson 2 2011 The grains in sandy soil are big so water will run through quickly The grains in clay so are small so water will run through quickly and B Keagh S Naylor Explanation E a The rate of drainage through the soil depends on the size of the air spaces and this depends on the size of the grains in the soil Since sand grains are considerably bigger than grains of clay the sandy soil will have bigger air spaces and the water will run through more quickly The situati
101. rambied one ingr must be You mix it up with a spoon so it must be n a mixture Perhaps it s a mixture of compounds You can t separate it so it must be compound Explanation D 5 Naylor and B Keogh e S This cartoon deals with the nature of a pure element a pure substance containing only one type of atom a compound two or more substances combined and a mixture two or more elements or compounds mixed together Confusion is quite likely because eggs are not made from a single pure substance Eggs are made up of a complex mixture of compounds which are changed chemically during heating You can review the definitions of elements compounds and mixtures and let students find out more about the chemical makeup of eggs and to look at how the white and yolk are each affected separately by heat This cartoon can be combined with a card sorts activity or a concept test to deepen students understanding Student Centred Approaches for Science Education Part 2 111 73 Muddy waters Link with curriculum Grade 8 chapter 2 lesson 2 2010 Explanation p vj Ue The issue is whether filtering traps dissolved and non dissolved substances Generally dissolved substances can pass through filter paper with no difficulty Related is the question whether water which looks clean is actually pure water and safe to drink The effectiveness of different filters can be investigated by comparing the appearance of the liq
102. rderly repeating sodium and chlorine ions This structure is caused by the electrostatic attraction between negatively and positively charged ions and gives salt grains its cubic shape The ions are closely locked into position and can only vibrate There is empty space between the atoms in the crystal but it is not filled with air The material is pure salt not a mixture of salt with air The lines that are sometimes used in drawings or models are not actual physical structures but they representations of the attraction among the ions Example 13 Forces Link with curriculum Physics Grade 8 chapter 2 lesson 1 2010 A person pulls a box across the floor Which statement is correct A The box moves forward because the person pulls forward slightly harder on the box than the box pulls backward on the person B Because action always equals reaction the person cannot pull the box the box pulls backward just as hard as the person pulls forward so there is no motion C The person gets the box to move by giving it a tug during which the force on the box is momentarily greater than the force exerted by the box on the person D The person s force on the box is as strong as the force of the box on the person but the frictional force on the person is forward and large while the backward frictional force on the box is small Answer D is correct The force exerted by the person on the box is equal to that exerted by the box on the person
103. re is only one light source and no indirect light 2 There is an orange shadow behind the orange card This statement refers to confusion between shadow and light The shadow can have an orange shade when there is sufficient indirect light In that case the reflected light on the orange card can reach the shadow region 3 The orange glass has an orange shadow This is correct if it means that the orange spot is the shadow of all the non orange light frequencies 4 There is no shadow behind the glass only light This is correct when you only focus on the point of view of the light The filter lets the orange frequencies of the light pass giving a light spot Conclusions Usually shadows are defined as the region which the direct light of the light source cannot reach Since people focus on only one light source the notion of black shadows is widespread However the extreme situation where there is absolutely no light reaching the shadow region is quite rare Look at the shadows around you and you will see the colour of the substrate e g the dark green shadows on grass This means that there is still light that reaches the shadow region This can be light from multiple reflections even blue light reflected by the sky or from other light sources Most people will say that the orange spot behind the orange filter is not coloured shadow but coloured light This is only partly correct because the shadow point of view also makes s
104. refore be necessary for the astronaut to be roped onto the space rocket Although s he will be attracted by the gravitational attraction of the rocket the size of this force is much too small to prevent the astronaut from floating away There are no practical investigations that directly address the situation shown Enquiry is likely to focus on thought experiments and reasoning by analogy Student Centred Approaches for Science Education Part 2 56 23 Ski Slope Link with curriculum Grade 9 chapter 2 lesson 2 2011 I THINK WE ALL GO AT THE SAME SPEED I THINK WHOEVER HAS THE BIGGEST SKIS WILL GO FASTER I THINK I WILL GO FASTEST BECAUSE I M THE LIGHTEST I LL GO FASTEST DOWN BECAUSE I M THE HEAVIEST Explanation E b y Sliding down a hill involves acceleration due to gravity So like the falling bungee jumpers cartoon 14 the weight of the skier will not make any noticeable difference to the speed of sliding down the hill As with the feather and paper cartoon 15 air resistance is more important The size of skis can affect the skiers control but will not affect the speed of sliding They will all ski down the slope at the same speed The situation can be modelled by sliding objects down a ramp to find out whether the weight of the object makes any difference to the speed of sliding A useful arrangement is to use a piece of curtain rail as a track and to roll marbles or balls down it Student Centred App
105. riends discuss why we have seasons on Earth These are their answers A In Summer the Earth is closer to the Sun B In Summer the Earth s northern axis is tilted toward the Sun C In Summer the Sun gives off more energy D In Summer the Sun shines longer E In Summer the Sun is directly overhead at noon In Summer the Sunlight is bended so it falls more directly on Earth Student Centred Approaches for Science Education Part 2 125 The best answer is B The tilted axis of the Earth causes parts of the Earth to receive more Sunlight than others Answers D and E are consequences of the tilted axis The slightly differing distance to the Sun does not have any effect on the seasons and neither have the variations in the Sun s output Example 3 Solar Eclipse Link with curriculum Earth and environmental science Grade 8 chapter 3 lesson 3 2010 During a solar eclipse parts of the Earth experience darkness for a brief time during the day Throughout time people have had different ideas about what happens during a solar eclipse A The Sun passes between the Earth and Moon B The Earth passes between the Sun and the Moon C Clouds block out the Sun D The Earth s shadow falls on the Sun E The Moon s shadow falls on the Earth F The Sun shuts off light for a few minutes G Sun moves behind the Earth for a few minutes then comes back again The best answer is E A solar eclipse occurs during a new Moon wh
106. ring a headstand The heart will need to work harder to pump the blood this extra distance Similarly the blood may not return from the head as readily as it does normally There should be some visible signs of any changes in the pattern of blood circulation If blood leaves the feet more quickly than usual they will go pale If blood does not leave the head as quickly as usual then the face will go red If the heart has to work harder then the pulse rate should increase Each of these can be tested with a healthy volunteer Student Centred Approaches for Science Education Part 2 79 45 Babies Link with curriculum Grade 10 chapter 1 lesson 6 2008 The shell would be too thick for the baby to get out Why don t peopie lay eggs like binds do A pst Explanation pu a us There is no simple single answer to the question of why humans don t lay eggs Internal development is safer and more efficient potentially resulting in larger offspring that can be more highly developed when they are born A human egg would need a very thick eggshell to protect it and this might be a problem for the baby to break through If humans did lay eggs they would also have developed other adaptations such as burying their eggs protecting them or making nests of some sort to lay their eggs in There is no experimental investigation in this situation Discussion into how a range of different animals reproduce will help to show how h
107. rming and cooling the balloons Student Centred Approaches for Science Education Part 2 65 32 Balloon Link with curriculum Grade 7 chapter 4 lesson 4 2009 THE MORE I BLOW THE BALLOON UP BALLOON 5 NAYLOR rtevel THE HEAVIER IT GETS AND B KEOGH PA a AIR IS LIGHT SO BLOWING THE AIR IN MAKES THE BALLOON LIGHTER THE AIR DOESN T WEIGH ANYTHING SO IT S STAYS THE SAME WEIGHT Explanation B h A common misconception is that air has no weight or that it has negative weight Like all substances air is made of particles and these particles although very tiny do have a small amount of weight Since air does have weight filling the balloon with air will make it heavier The more air it contains the more it will weigh Student Centred Approaches for Science Education Part 2 66 33 Lemonade Link with curriculum Grade 7 chapter 4 lesson 4 2009 LEMONADE S NAYLOR AND B KEOGH I THINK IT WILL STAY THE SAME WEIGHT Explanation A common misconception is that gases have no weight or that they have negative weight When the cap is taken off the lemonade bottle carbon dioxide gas will escape Like all substances carbon dioxide gas is made of particles with a small amount of weight The lemonade will weigh less when the gas has escaped Although some air may dissolve in the lemonade and replace some of the carbon dioxide there will still be an overall weight loss With a sensitive scale
108. roaches for Science Education Part 2 57 Heat 24 Boiling water Link with curriculum Grade 7 chapter 1 lesson 1 3 2009 BOILING WATER CBASED ON S NAYLOR AND B KEOGH f rtevelde THE LITTLE PAN HEATS UP FASTER SO THE WATER WILL Ys BE AT A HIGHER TEMPERATURE i WHEN IT BOILS THE WATER IN THE LITTLE PAN WILL BOIL FIRST THE TEMPERATURE OF THE BOILING WATER IN THE BIG PAN WILL BE HIGHER Explanation cid A common misconception is that small amounts of liquid will boil at a lower temperature than larger amounts It takes less energy to boil a smaller amount of liquid so small amounts will boil more quickly but the boiling temperature will be exactly the same The situation can be investigated using a container for boiling water It is possible to compare the time taken to boil and the boiling temperature using different amounts of water The effect of heating the water more strongly can also be measured The ideal way to heat the liquid is to use a small heater since it can be difficult to control how much energy is supplied A useful extension is to compare the boiling time and temperature using other liquids such as a salt solution or milk Student Centred Approaches for Science Education Part 2 58 25 Snowman called Ice and cloth in Khmer version Link with curriculum Grade 7 chapter 1 lesson 1 3 2009 SNOWMAN CS NAYLOR AND B KEOGH DON T PUT THE
109. s and the mechanisms behind it yet still have the common misconception that a chemical bond is a structural component or a glue like form of matter Example 12 Structure of Atoms Link with curriculum Chemistry Grade 8 chapter 1 lesson 1 2008 A group of friends is looking at grains of salt through a magnifying glass They are wondering what they would see if they had a device powerful enough to see the individual atoms These are their answers Student Centred Approaches for Science Education Part 2 130 A The atoms would be packed tightly together They would look like a solid material without any empty spaces between the atoms B would see vibrating atoms arranged in an orderly way with spaces between them There would be nothing in the spaces not even air C think would see atoms not moving and arranged in an orderly way There would be space between the atoms The space would be filled with air D think would see atoms in the shape of small cubes Each of these cubes would join together to form a larger cube of salt E think would see lots of vibrating atoms connected together by little lines The lines connecting each atom give them a definite cube shape F think would see individual atoms moving from place to place They would be moving all about the inside of the crystal shape The best answer is B salt is an example of a crystalline ionic lattice A salt crystal is made up of a structure of o
110. s caused by adverse environmental conditions which somehow attack organic material Few students are generally able to point out what happens during the rotting process In fact organic material rots because microbes microscopic organisms such as bacteria feed on it This may not be obvious because microbes are invisible to the naked eye However the amount of moisture the temperature and acidic conditions can all influence how rapidly the microbes feed on the apple and cause it to rot The speed of rotting of an apple can be investigated by leaving it on the surface of different types of soil and in a range of different conditions The action of microbes can be prevented by using a disinfectant solution or a bactericidal spray to sterilize the apple every few days Student Centred Approaches for Science Education Part 2 78 Human body 44 Headstand Link with curriculum Grade 8 chapter 3 lesson 4 2010 If you stand on you Your bran will get head your feet won t oc euch blied Get any blood S Naylor and B Keogh Your heart will differ 0 need to heart of your blood harder circulation fim EJ Explanation How does blood get to the head normally Since the head is above the heart it seems that the heart must be able to pump blood upwards against gravity suggesting that the feet will continue to get blood during a headstand However the distance that the blood needs to be pumped will be greater du
111. solved in the water Student Centred Approaches for Science Education Part 2 88 54 Variation Link with curriculum Grade 12 chapter 6 lesson 1 2010 Where does genetic variation come from Genetic variation is produced by changes in the DNA ee Genetic variation is produced by Genetic variation natural selection is the result of adaptation think you are all correct Explanation y Character A is correct although mutation is only one of two sources of genetic variation the other is sexual recombination Answer B and C are not accurate because the relation is the other way around Natural selection works on variation that already exists and the same is true for adaptation Variation allows adaptation and natural selection to take place Student Centred Approaches for Science Education Part 2 89 55 Variation 2 Link with curriculum Grade 12 chapter 6 lesson 1 2010 Are we all the same inside Any differences inside come from changes in how we grow Genes are not involved Although we loo different on the outside we are all the same inside think that we have differences My blood type is different from my sister s There are male and female differences but that s all Fisher Anderson Explanation F F A UI Character C is correct and various blood types are just one example of human variation Answer A reflects the common idea that althoug
112. son 2 amp 3 2011 THE SHADOW IS TWICE AS DARK WHERE THE SHADOWS OVERLAP THE SHADOW IS SUST SAME WHERE THE SHADOWS OVERLAP THE SHADOW IS A BIT DARKER BUT NOT TWICE AS DARK Explanation e A shadow is caused by the absence of light If two shadows overlap the darkness of the two shadows would not normally result in a darker shadow With the trees the situation is complicated by the fact that the trees don t cast a complete shadow because of the number arrangement and thickness of the leaves The shadow will therefore be more complete where the two trees overlap even if it is not darker Observation of actual shadows cast by trees is not difficult and the situation can be modelled using card or paper models to cast a shadow Comparing shadows made by overlapping opaque translucent and transparent objects is an interesting extension to the activity With transparent objects some light will be absorbed to produce a faint incomplete shadow so overlapping transparent objects will produce a darker shadow Student Centred Approaches for Science Education Part 2 39 6 The colour of shadows Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 THE COLOUR OF SHADOWS BASED ON S NAYLOR AND B KEOGH rtevelde THE ORANGE CARD 2 hogeschool MAKES AN ORANGE SHADOW Den THE ORANGE FILTER MAKES AN ORANGE SHADOW THE FILTER DOESN T MAKE ANY SHADOW THERE IS ONLY LIGHT Explana
113. son pushes each car for 5 s Ignoring friction and assuming equal force exerted on both cars the kinetic energy of the light car after the push is A Smaller than B Equal to C Larger than The kinetic energy of the heavy car The correct answer is C Because the momenta of the two cars are equal the car with the larger velocity must have the larger kinetic energy This will be the lighter of the two because it has less inertia its acceleration is larger than that of the heavy car Example 22 Catching a cold Link with curriculum Biology Grade 9 chapter 4 lesson 2 2011 Four students discuss how you catch a cold get sick Here are their answers A You can get a cold when you re having a fever B You can get a cold from being cold and wet C A cold is caused by germs virus D Not getting enough sleep can make you catch a cold The correct answer is C Viruses and bacteria are agents of infection A fever is a physiological response from the body to the infection Being cold and wet and not getting enough sleep can weaken your immune system and thus make it easy for viruses to infect your body Example 23 Antibiotics Link with curriculum biology Grade 12 chapter 6 lesson 1 2010 Many strains of bacteria are now resistant to antibiotics How has antibiotic resistance among bacteria become so widespread A Since a lot of people use antibiotics bacteria need resistance to survive So they develop resistance B
114. st answers are D E and G When grains of sugar are added to the water they form a mixture called a solution Sugar molecules become surrounded by attracted polar water molecules breaking apart the sugar molecule crystal When sugar dissolves it is physically not chemically combined with water and therefore it does not form a new compound Dissolving is different from melting because melting involves a change of state and does not require the interaction between two substances as dissolving does According to the conservation of mass principle the mass of sugar remains the same even though it cannot be seen in the solution Example 11 Chemical bonds Link with curriculum Chemistry Grade 10 chapter 3 lesson 1 2008 Four students were discussing their ideas about chemical bonds This is what they said A think a chemical bond is produced by a molecule It is a substance made up of matter that holds atoms together B think a chemical bond is an attraction between atoms It is not made up of matter C think a chemical bond is a structural part of an atom that connects it to other atoms D think a chemical bond means that atoms are combined into bigger atoms The best answer is B Chemical bonds are formed between atoms as a result of an attraction between their electrons The bond exists as an attractive force between the atoms where electrons are transferred or shared Many students can define the different types of chemical bond
115. t Centred Approaches for Science Education Part 2 127 G Chlorophyll The best answer is D but also B is partially correct The test is designed to reveal whether students recognize that a gas from the air CO3 is combined with water and transformed into the new material that makes up most of the matter in the tree The mass contributed by CO is much greater than the mass contributed by the water Example 7 Digestive system Link with curriculum Biology Grade 7 chapter 4 lesson 1 4 2009 Grade 11 chapter 4 lesson 2 2009 A group of students is discussing the main function of the digestive system Which statement captures best your opinion A The main function is to release energy from food B The main function is to help us breathe C The main function is to break food down into molecules that can be absorbed by cells D The main function is to break food down in the stomach into small pieces of food that can be used by the body E The main function is to carry bits of food and nutrients to all the different parts of our body F The main function is to store food so that we can get energy when we need it The best answer is C The digestive system has two major purposes to break down food and to prepare nutrients for absorption by cells The digestive system carries out 6 basic functions taking food in ingestion secretion movement of food and wastes break down of food absorption from the gastrointestinal tract t
116. t moving objects have force acting on them in the direction of movement With the football the only forces acting when it is in the air are gravity and a small force due to air resistance In theory it would never come down if you could kick it hard enough like satellites can stay permanently above the Earth but in practice this is not possible It is not easy to directly measure the forces on the ball while it is in flight There are no obvious practical investigations that directly address the situation shown Enquiry is likely to focus on modelling some aspects of the situation e g looking at the forces involved in horizontal motion Student Centred Approaches for Science Education Part 2 51 18 Space rocket Link with curriculum Grade 8 chapter 2 lesson 3 2010 NOW THAT WE RUN OUT OF FUEL THE ROCKET WILL SLOW DOWN THE ROCKET GRADUALLY WILL SUST FLOAT IN SPACE IT WILL CARRY ON MOVING AT IT WILL FALL Towaeos THE THE SAME SPEED NEAREST PLANET Explanation E p I v Ye Although friction acts to slow down moving objects on Earth in space there is no atmosphere and therefore no friction although there may still be gravity The space rocket will keep moving at the same speed and in the same direction when its fuel runs out If it is close enough to another star or planet to be affected by their gravitational field then it will gradually fall towards the star or planet In some respects the
117. the boots are part of a completely airtight suit gravity is not important If the astronauts were likely to float away then the boots wouldn t make much difference Actually the boots are as light as possible in order to avoid using extra fuel bringing them to the Moon Student Centred Approaches for Science Education Part 2 101 Spacewalk same as Physics Link with curriculum Grade 12 chapter 2 lesson 3 2011 rtevelde hogeschool I YOU WILL PUSH GENTLY YOU WILL SOON STOP IF I PUSH OFF I WILL FLOAT FOR EVER YOU WON T BE ABLE TO PUSH OFF THERE IS NO FRICTION IN SPACE YOU DON T NEED TO WORRY THE GRAVITATIONAL ATTRACTION OF THE ROCKET WILL BRING YOU BACK Explanation 7 A good understanding of how forces operate is vital for astronauts who make spacewalk Pushing off in any direction will result in the astronaut just floating away since there is virtually no air resistance to prevent movement It will therefore be necessary for the astronaut to be roped onto the space rocket Although s he will be attracted by the gravitational attraction of the rocket the size of this force is much too small to prevent the astronaut from floating away There are no practical investigations that directly address the situation Enquiry is likely to focus on thought experiments and reasoning by analogy Student Centred Approaches for Science Education Part 2 102 66 Luna
118. time efficient but lacks the break out sessions in small groups that activate students MY SHACOW IS BIGGEST WHEN I AM YOUR SHADOW IS CLOSE THE SCREEN BIGGEST WHEN YOU ARE CLOSE TO THE LAMP YOUR SHADOW WILL CISAPPEAR WHEN YOU STAND IN FRONT OF THE LAMP THE SHADOW IS THE SAME NO MATTER WHERE YOU STAND Objectives To stimulate discussion of scientific ideas among student teachers To activate student teachers prior knowledge To detect and correct student teachers misconceptions Material needed Concept cartoon printed or projected on a screen A projector or torch as a light source for inquiry and verification for this cartoon Student Centred Approaches for Science Education Part 2 16 Step by step instructions 1 Show the concept cartoon to the students and explain the context 2 Give students a short time for individual reflection while they read the statements try to answer these questions a With whom do you agree b Is than one idea correct Why is this question important Students need to think about why a certain answer is correct or not Maybe a statement is only partly true This reflection time can be accompanied by small experiments C Try to construct a definition of shadow 3 Do a quick scan to see what the group is thinking e g by raising hands or using voting cards 4 Organize a discussion with the whole class All possible answers ar
119. tion E CJ In most circumstances a shadow is simply the absence of light so shadows usually are black A coloured filter absorbs some of the light but light of a particular colour passes through The shadow will then be an area of reduced and coloured light An orange filter will let orange light pass through and produce an orange shadow Since the orange card blocks all light its shadow will be darker than that from the filter It is possible to set up simple tests to determine the colour of the shadow cast by different objects Placing the objects on a white surface will help to make the shadows more visible If a glossy card is used then the situation may be complicated by reflection from the surface of the card so that there may be a faint orange tinge to the shadow Interesting comparisons could be made between the shadows cast by dull or reflective surfaces by opaque or transparent materials and by a white or coloured light source Student Centred Approaches for Science Education Part 2 40 7 Solar eclipse Link with curriculum Grade 9 chapter 5 lesson 2 amp 3 2011 f A rtevelde hogeschool ECLIPSE S NAYLOR EN B KEOGH ie E I THINK WE GET AN WE GET AN ECLIPSE WHEN ECLIPS WHEN THE ONE OF THE PLANETS PASSES BETWEEN THE EARTH AND THE SUN I THINK IT HAPPENS WHEN THE SUN PASSES BETWEEN THE EARTH sone THE SHADOW OF THE MOON FALLS ON THE EARTH THE SHADOW
120. to melt A useful extension would be to investigate the rate of melting at different temperatures to show that the bigger ice cube takes longer to melt whatever the outside temperature as long as it is the same for each cube Students can analyse this quantitatively using various ice volumes and or temperatures and plot their results in a graph Student Centred Approaches for Science Education Part 2 64 Fluids 31 Helium balloon Link with curriculum Grade 7 chapter 1 lesson 2 2009 MY HELIUM BALLOON HELIUM BALLOON DOESN T FLOAT S NAYLOR AND B IT WILL FLOAT IF ANYMORE 5 YOU COOL IT IN THE FREEZER IT WILL FLOAT IF YOU LET SOME OF THE HELIUM IT WILL FLOAT Ai IF YOU WARM IT WITH HAIR DRYER Explanation Students find it in general more difficult to understand floating in air than floating in water In this case the helium is buoyant compared to air In other words it weighs less than a similar volume of air so a balloon full of helium will float in air The situation is complicated by thermal expansion and contraction When the balloon is warmed its volume increases its density decreases and it will float better The reverse occurs when it is placed into a freezer Very few commonly occurring substances are lighter than air If helium balloons are available you can investigate the situation A range of enquiries can be undertaken including observing the effect of letting some helium out wa
121. toons and concept tests are student misconceptions Students come to class with prior knowledge on the topic They acquire this from TV family books culture or prior lessons Sometimes this knowledge is incomplete or incorrect Sometimes it makes sense to the students because it s more intuitive or because they have been familiar with it for a long time Let s take Newton s First Law as an example When observing an object in rest on a table it s more intuitive for students to assume that no forces are working on the object than accepting that there are multiple forces keeping each other in balance Newton s First Law is counterintuitive due to the presence of air resistance For a teacher it s important to acknowledge this prior knowledge and to devise instructional strategies to elicit and change it Merely telling students that their viewpoint is incorrect is unlikely to change it Student Centred Approaches for Science Education Part 2 13 but will rather create a difference between their school view and their view outside school They will accept Newton s Laws in the class but will return to their old views outside class Various terms are used to describe this incorrect prior knowledge such as misconceptions preconceptions and naive knowledge In this manual we will apply the term misconceptions because it indicates clearly the incorrect character of the knowledge What are concept cartoons Concept car
122. toons are simple drawings which put forward a range of viewpoints THERE ARE NO THERE ARE SHADOWS AT NIGHT about the science involved in everyday C MEE gu situations In this example an experiment about shadows is described Four cartoon characters try to predict the result of this experiment based on their own ideas about shadows These possible answers are based on popular student misconceptions In this way the opinions J expressed will sound familiar to learners 228 and they will easily identify themselves with one of the viewpoints The main objectives of concept cartoons are stimulating learners to think discuss raise new questions investigate and bring up arguments Concept cartoons are more than mere multiple choice questions They are instruments to trigger student involvement thinking and exploration All answers represent frequent misconceptions that occur among learners and should therefore be given attention during class It is very important to notice that all possible answers in the cartoon have equal status Learners have to try to select and specify the best concepts about the situation This process of conflict between different viewpoints is an important aspect of gaining scientific knowledge For this reason this method is appropriate for constructivist student centred teaching 2 Objectives You can reach different objectives depending on how you apply cartoons in your lesson
123. ucation Part 2 124 6 Examples We include a set of 23 examples from a variety of curriculum topics Many more examples be found on internet or in the library see the links at the end of this chapter It should be noted however that all examples are to be considered as starting points You should evaluate each Concept test after its use Answer categories that are never chosen should be deleted and answers that reflect misconceptions present with your students should be included Stimulate your colleagues to introduce Concept tests in their lessons and share your tests with each other Example 1 Why is it dark at night Link with curriculum Grade 8 chapter 3 lesson 1 2010 Six friends were wondering why the sky is dark at night This is what they said A The clouds come in at night and cover the Sun B The Earth spins completely around once a day C The Sun moves around the Earth once a day D The Earth moves around the Sun once a day E The Sun moves underneath the Earth at night F The Sun stops shining at night The reason for the day night cycle is that the Earth spins completely around its axis approx every 24 hours answer B When our location on Earth is turned away from the Sun we have might darkness When our location on Earth is turned toward the Sun we have day daylight Example 2 Seasons on Earth Link with curriculum Earth and environmental science Grade 8 chapter 3 lesson 1 2010 Six f
124. uid which passes through the filter Using filters such as cotton wool a fine sieve and filter paper of various thicknesses will provide a basis for comparison Water that looks clean can be completely evaporated to demonstrate that different substances can still be present in the water without affecting its appearance You can link this cartoon to the topic of water pollution Is rain water safe to drink and what should we do to make it safe to drink Student Centred Approaches for Science Education Part 2 112 74 Condensation Link with curriculum Grade 7 chapter 2 lesson 1 2009 Maybe the ice has melted on the outside of the glass The glass gets wet nh S Navior and B Keo think the water vapour in the air h s think that some of the water must have leaked turned into drops of out of the glass water on the glass Explanation e aA EJ Although condensation is a common experience it is not obvious where the condensed water comes from Water vapour is present in the air but is invisible At higher temperatures the water vapour is likely to remain as a gas but at lower temperatures it can condense to droplets of liquid A glass containing ice is normally cold enough for water vapour in the air to turn into droplets of liquid on the side of the glass You can use various practical activities to explore the situation Taking an empty cold glass out of a freezer can show that the ice in the g
125. ulate groups to reach consensus When they reach a consensus very quickly tell the group that other viewpoints are also correct in some circumstances Students try to figure out under which conditions each statement is valid Ask again for some brief feedback about the range of views present for example by having a new vote 3 Organize a class discussion about how we could find out which alternative s are valid and under which conditions If necessary stimulate the discussion with the following questions What is the definition of shadows Is this definition applicable to shadows in daily life Can we make the definition more general 15 shadow of a person on a coloured background like grass black When there is only red light in a room will the shadows be red Do you understand why shadows on white snow look blue 4 Small group inquiry Students work together in small groups to set up experiments to test the various statements They record the experiments observations and conclusions Afterwards students present their outcomes to the class including which alternative s seem s acceptable and what further information we might need to be sure 5 Combine all ideas together and make a synthesis of the initial problem the inquiry the outcome and what has been learnt Student Centred Approaches for Science Education Part 2 27 Explanation of statements 1 Shadows are always black This is only correct when the
126. uman reproduction is consistent with developments in other animals Student Centred Approaches for Science Education Part 2 80 46 Antibiotics Link with curriculum Grade 11 chapter 3 lesson 2 2009 Why aren t antibiotics as effective as they used to be 1960 2000 4 Bacterial infection 0 years Bacterial infection Antibiotics to the rescue i Let s hope these antibiotics work this time I m really sick Antibiotics are It s just that the must be resistant heard bad They make antibiotics kill all to antibiotics that the antibiotics monster germs the sensitive are getting weaker bacteria and then the resistant ones multiply Fisher Anderson Explanation IHNEN This cartoon topic is something that students may have heard about at home and may think that they understand Character C is correct All bacteria do not acquire resistance and people do not become resistant to antibiotics although the bacteria inside them can This cartoon helps to explain why it is important to take antibiotics long enough when you are sick If you stop taking it too early not all the bacteria will be killed The remaining bacteria may develop resistance and spread to other people who can then not be cured anymore with this type of antibiotics Student Centred Approaches for Science Education Part 2 81 Evolution and reproduction 47 Dominance Link with curriculum Grade 11 chapter 3 lesson 2 2009
127. w that a chemical reaction is occurring and producing entirely new materials which were not present at the start of the reaction Student Centred Approaches for Science Education Part 2 119 80 Burning Candle Link with curriculum Grade 9 chapter 2 lesson 2 2011 think that the wax vapour burns not the When candle is burning the wax melts P and the wick burns wick x a gt c m 5 gt z that the wa The was think that the w x 5 aN vapour and the wick there to hold up fh both burn the wick E Explanation E u Although watching a burning candle is experience understanding what is happening when the candle burns is not obvious A common misconception is that the wick burns and the wax are only there to hold up the wick Actually both the wick and the wax burn The wax melting is visible but the wax vaporizing and burning is not Careful observation of the candle leads to the question of where the wax has gone A useful approach is to find other ways of burning the wax such as using a match or a piece of card as an alternative to a wick in some molten wax Student Centred Approaches for Science Education Part 2 120 Concept Tests amp Peer Teaching 1 Introduction What are Concept Tests 4 Fi What are Concept tests Concept tests are challenging multiple choice questions that focus on conceptual understanding on a k

Chapter 4: Conceptual Science Teaching

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