37 Software for the Leicester Interactive Videodisc project
Contents
1. demonstrated at CAA89 The final version of the software will be available not later 528 SOFTWARE FOR THE LEICESTER INTERACTIVE VIDEODISC PROJECT than the summer of 1989 and it is hoped that wider usage of the system will take place during the following academic year 37 16 Conclusion The Leicester project seeks to solve a significant problem in handling archaeological information for teaching purposes The solution will be applicable in any discipline where large amounts of illustrative material are used such as geography geology and medicine It will make available at low cost ways of using information which were not practicable before the development of videodisc technology References MARTLEW R D 1988 Optical disc storage another can of worms in Ruggles C L N amp Rahtz S P Q eds Computer and Quantitative Methods in Archaeology 1987 International Series 393 pp 265 268 British Archaeological Reports Oxford RICHARDS J D amp N S RYAN 1985 Data Processing in Archaeology Cambridge University Press Cambridge 529 Cak H ile cain DAN Paneth ty ee eee rrr iments sy Sulton deal oS ARA acre vin amp Ka 3 Sk Loe iwe ret Ri fric ke ie nie it z gt a 0 NON Meit pacers Bi ea y aa je mets E avs y fateh pui Je 5 i ver iais an r Ad mi pet of a CET IN B2. a short caption which must be provided by the configurator This is for identification purposes e g when setting up a carousel or tutorial Still frames including those within grids walkabouts and sequences may also have a default caption again provided by the configurator for display with the videodisc frame 533 CLIVE RUGGLES A 5 Structure of a carousel A 5 The carousel feature provides support for the notion of a tutorial see Section A 6 below but does not itself constitute a means whereby a tutor and student can interact A 5 2 A carousel is a sequence of videodisc frames Once constructed it may be stored for subsequent viewing by other users A S Each frame within a carousel may be captioned or uncaptioned A caption may be either the default caption see Section A 4 4 or an alternative specified when the carousel is constructed It may either be displayed in the default position on the screen or elsewhere as specified when the carousel is constructed A 5 4 Information about a carousel is stored in a carousel file which when loaded by the user within the system enables a carousel to be viewed or edited A 6 Structure of a tutorial A 6 A tutorial provides interaction between a tutor and student in a structured manner The degree of constraint upon the student may be determined by the tutor One extreme would constitute a rigid computer aided learning CAL facility The other would allow unrestric
3. are a subsidiary item of their parent Items may have zero or more subsidiaries 8 The relationship between a parent and subsidiary item concerns individual frames within the items and may be complex The following rules however apply generally a The relationship concerns only a single entry within the parent item hereinafter the parent entry b One or more frames within the parent entry may be parent frames 592 A LIVE PROJECT DRAFT SYSTEM SPECIFICATION c Each parent frame has one or more pick areas relating to the subsidiary item in question d A pick area is an area within a picture delimited by a closed polyline The pick areas for a given frame are non intersecting However when taken together they need not necessarily cover the entire picture e The pick areas for a given frame need not necessarily relate to the same subsidiary item f A given pick area relates to a particular frame within the subsidiary item concerned The Subsidiary item operation see A 9 3 prompts the user to identify a pick area within the current frame If done successfully the related frame in the subsidiary item becomes the current frame The Parent item operation see A 9 3 selects a frame from the parent item and it becomes the current frame If the existing current frame is the subsidiary of a frame within the parent item then that frame is selected Otherwise the startup frame of the parent entry is displayed Example
4. assess the overall success or otherwise of the system 37 6 Some problems with existing systems In many existing interactive videodisc systems the control software is specific to a videodisc This is scarcely surprising in the case of many of the systems used in industry since they are produced in order to teach a management trainee about a specific problem The same is in fact true of the BBC Domesday system both the database and the control software are specific to the system In fact both are encoded onto the two videodiscs and are not obtainable separately This approach is understandable in the case of a commercially marketable videodisc system where financial concerns are paramount and software piracy a major concern It does however place strong restrictions on portability and updateability Videodisc mastering is expensive although once it is done obtaining copies of the videodisc is relatively cheap If the associated database and or control software are encoded onto the videodisc they can not be updated or amended without a new disc being mastered at great expense Authoring programs and videodisc systems whose software includes authoring facilities have recently started to appear However they are often highly specific to a particular subject area user unfriendly and tied to particular hardware configurations 37 7 Objectives of the Leicester project The most immediate objective of the Leicester project is to produc
5. 1 A map might contain several archaeological sites Each site might be enclosed within a small pick area Each pick area would relate to the startup frame of the first entry in a subsidiary item which might consist of pictures of the site walkabouts or larger scale plans related together into grids Example 2 An entry might consist of a grid of maps at small scale A subsidiary item might consist of a single grid of maps at larger scale Each frame in the parent entry would comprise pick areas which when selected would cause the relevant larger scale map to be displayed The structure described here is specified in VDM metalanguage in a separate Formal System Specification document A 4 2 The abstract videodisc structure may though in general it will not link frames in different chapters or on different sides of an actual videodisc or even link frames on separate videodiscs See also 1 A 4 3 It is likely that an abstract structure relating to a collection of images will be configured by the person who compiled the collection for mastering Configuration will be achieved using the LIVE configuration program Note however that no abstract structure is unique existing structures may subsequently be extended or edited using the configuration program and different abstract structures might be constructed relating to the same collection of images or to different collections with some images in common A 4 4 All entries have
6. 37 Software for the Leicester Interactive Videodisc project Clive Ruggles 37 1 Introduction The Leicester Interactive Videodisc project funded by the University Grants Committee under their Computers in Teaching Initiative aims to investigate the application of interactive videodiscs in the teaching of archaeology to undergraduates This paper describes progress on the software development for the project 37 2 Interactive videodisc technology Interactive videodisc technology is ideal for developing the skills of interpreting visual material which are so fundamentally important in archaeology but which all too fre quently can not feasibly be taught in the field or by handling actual objects Videodiscs can provide a comprehensive collection of visual information a single videodisc can hold over 100 000 high quality images each one being directly accessible with an access time of at most a few seconds In addition to still frames collections of frames forming moving sequences may also be stored The still frames or moving sequences may then be displayed on a television screen or on a computer screen overlaid with standard computer generated text or graphics When controlled by a microcomputer program and linked up to a conventional database interactive videodisc technology provides very powerful and flexible methods of managing and retrieving visual and related textual and numerical information One could envisage for example art
7. Computing Studies At each Stage the Specification has been extensively discussed within the project s Management and Steering committees Part of the system the Browse Videodisc option see below has been specified using the Formal Development Technique known as the Vienna Development Method VDM Design work has proceeded apace and the first skeleton implementation is already completed The choice of hardware networked RM Nimbus PC1 workstations of design method ology and of programming language for software development work Modula 2 re flect the ability to take advantage of experience and existing program libraries in the Department of Computing Studies Database facilities within our package would ideally be fully relational but since the user must possess a suitable off the shelf database package we must initially at least choose a widely used and generally available package For these reasons the database management part of the pilot system will be programmed using dBaselll There will be a facility to exit from the system to a standard Word Processing package for longer responses see Appendix Section A 6 4 37 11 Description of the software Part of the high level specification is reproduced in the Appendix It consists of a description of the structure of the system Sections A 1 to A 7 and an overall description of the top level options Section A 8 There are nine of these options one Browse Videod
8. T SYSTEM SPECIFICATION A 8 5 Help is a generic operation available to a user at any time When invoked other than from the top level menu however only the information relevant to the current situation will be available A 8 6 Only Browse database involves access to the database with the exception of other operations when they invoke Browse database Make carousel and Make tutorial will invoke an in house screen editor A 9 Browse videodisc A 9 1 The operations within this option may be invoked in three different ways 1 using drop down menus 2 using keyboard characters and 3 using mouse shortcuts see A 9 5 below All available operations may be invoked at any time by methods 1 or 2 most available operations may also be invoked at most times by method 3 A 9 2 The operations allow the user to display frames by moving about the various abstract structures described in Section A 4 of Part I The available options at any time are indicated by those drop down menu options which are highlighted Initially the startup frame of the first entry in the top item is shown A 9 3 Drop down menu selection Ad Sak The menu bar will contain the following menu headers LIVE Tree Item Entry Options Measure where Entry is Grid Walkabout Movie Sequence or SingleFrame depending upon the nature of the current entry The drop down options within the various menus are as follows LIVE Tree Item Browse Videodisc T
9. The user is prompted to indicate a sequence of points using the mouse cursor The left button is used to indicate all points but the last the right button is used to indicate the last point Straight lines are drawn joining each point to the next The distance along the polyline is displayed 4 Measure area This option is only available if scales have been defined The user is prompted to indicate a sequence of points using the mouse cursor as above Straight lines are drawn joining each point to the next and the last point to the first The interior area of the region demarcated in this way is displayed A 506 selecting Exit to WP Help or Quit from the LIVE menu will have the effects described in A 8 4 A 8 5 and A 8 2 respectively A 9 4 Keyboard selection All operations will also be invokable by using sequences of keyboard characters following the escape character When the escape key is pressed prompts will appear listing the available options For example ESC T T will invoke Top item under Tree ESC will invoke Help A 9 5 Mouse shortcuts selection A 9 5 1 Most operations will also be invokable by clicking the mouse with the cursor in suitable response areas on the display screen This feature is intended for the user who has become familiar with the system through the use of menu operations and now wishes to short cut them wherever possible 339 CLIVE RUGGLES The general layout of the re
10. arious archaeological sites The abstract structure might be configured as follows The top item consists of a single entry a grid containing the two smallest scale maps The startup frame is the southern map The top item has a single subsidiary item This also contains a single entry a grid containing the intermediate scale maps The latter item again has a single subsidiary item This single third level item again contains a single entry a grid containing complete 1 50000 map coverage of Great Britain The third level item has many subsidiary items at the fourth and lowest level Each fourth level item contains pictorial coverage of a particular site An item on say Stonehenge might contain four entries an aerial photograph of the site single frame a sequence of plans showing its phases of construction and use sequence a walkabout of the site walkabout and a film of midsummer sunrise movie A 9 7 2 Use When Browse Videodisc is invoked the startup frame of the top item is displayed i e the map of the southern half of Great Britain The Stonehenge item might then be selected by three successive Subsidiary item operations In each case the relevant pick area is selected using the mouse in order to home in on the site The technique is similar to that used in the Domesday system When the Stonehenge item is first selected the startup frame of the first entry will be displayed This is the aerial photograph o
11. asuri paw zru azal why apin npe te gt day tutmas 6 mehi ragt ote aaa otunu is a cnr mt tar Urie aina DOOR AUR tenn phe ef e dii bn Tas at lamai Ota m any e rs 0 2 a ma ly Ae thy dt Trev dg ela yaa wT b rg ae ey tras th gi o IK on Cite ak m inj a iea ieee tare a YA paren Aen ore We eae aie vane Parie rere L Cappa tarpia fre hetsy star _ 19 Rm esoier Wis ou hell deen vate Well Ag im J ahe ait pate ohne 3 Lapse d Farge rl Aah chairs Fa A Leicester Interactive Videodiscs in Education LIVE project draft system specification Part STRUCTURE OF THE SYSTEM A 1 Overall structure of the system The software will consist of the following 1 A database of textual and graphical information 2 An indexed collection of pictures hereinafter frames 3 In house software to drive the system 4 An off the shelf database management system dBaselll in the first instance and an off the shelf word processing system such as Microsoft Word or WordStar 5 Carousel fil
12. ated by the cursor changing to a no movement possible icon 540 A LIVE PROJECT DRAFT SYSTEM SPECIFICATION Grids Adjacent frames in grids may be invoked by pressing either mouse button towards the appropriate edge or corner of the screen A double click in any position invokes Startup frame e Walkabouts The mouse cursor options are as follows Startup frame Double click in any direction Turn left right Left click towards left right of screen Move left right Right click towards left right of screen Move forwards backwards Left click towards top bottom of screen Show map Right click towards top or bottom of screen e Movies The mouse cursor options are as follows Banner frame Double click towards top or bottom of screen Run from start Left click towards top or bottom of screen Run from here Right click towards top or bottom of screen Freeze Double click towards left or right of screen Fast forwards Right click towards left of screen Fast backwards Left click towards left of screen Next frame Right click towards right of screen Previous frame Left click towards right of screen e Sequences The mouse cursor options are as follows First frame Double click anywhere in area Next frame Click either mouse button towards right or top of screen Previous frame Click either mouse button towards left or bottom of screen If an entry is unavailable
13. de facilities which allow a tutor to construct his own tutorials These so called authoring facilities are designed to enable tutors who are not necessarily computer specialists themselves to construct rigidly structured tutorials suited to their own needs from a large databank of visual material The tutor is allowed free exploration facilities and uses them to select sequences of videodisc frames interspersing them with his own comments and points where a response is required from the student e g to a multiple choice question and using some simple flow of control structures to construct different pathways depending on the response 37 5 Evaluation In the rigidly structured approach student responses may be directly monitored and students marked on the basis of these This sort of approach may be favoured where CAL exercises are used as part of a continual assessment assignment 524 a SOFTWARE FOR THE LEICESTER INTERACTIVE VIDEODISC PROJECT There is no mechanism for marking a student in such a direct way in the free exploration approach It is of course possible to monitor a student s use of the system and a tutor might wish to use this as the basis for assessment However it seems unlikely that a tutor favouring this sort of teaching methodology will be unduly concerned with the step by step assessment of individual students More probably such monitoring will be used as a class statistic enabling the tutor to
14. disc frames for information purposes and only eliciting choice screen position or single line responses More loosely constrained teaching programs can be constructed by making extensive use of free browse options for the student within tutorials arid by eliciting longer text responses 37 14 The abstract videodisc structure One of the main features of the Leicester software is the ability to impose an abstract structure upon the indexed collection of images stored on a videodisc This then gives the user the opportunity to browse the videodisc by moving about this abstract structure quite independently of the ability to browse the database and access videodisc frames by identifying relevant frame numbers in the database A specific example of such an abstract structure is provided by the BBC Domesday system where the user may browse Ordnance Survey maps moving up down left or right and zooming in or out to different scales Our abstract structure is much more general We have attempted to develop a simply understood but powerful and widely applicable abstract structure for the organisation of an indexed collection of analogue images The abstract structure is a hierarchy constructed from a few simple abstract concepts An example of the latter is a grid a collection of frames conceptually organised in a rectangular grid each frame having up to eight neighbours in the directions up left up and left etc The edge of a grid may be rag
15. e a working pilot system so that its use for teaching undergraduate archaeology can be evaluated in the short term Our longer term objective is to produce powerful and generally applicable software for the use of collections of images held on interactive videodiscs in higher education and training Since this software is intended for the public domain it is essential to make it available independently of the collection of images on a particular videodisc The same must be true of any database to be used in association with a particular image collection Different databases might then be used with a given collection of images or different collections of images with a given database the control software could be used with a number of different videodiscs and updated versions of the databases or control software could be distributed without causing any difficulties 37 8 Basic software requirements Our control software must be expandable and portable to different hardware config urations It must also be reasonably future proof while the storage and retrieval of 525 CLIVE RUGGLES high quality images is a stable development interactive videodisc technology is merely a particular way of achieving this and will before long be overtaken by alternatives We wish to minimise the user familiarisation necessary both for students and tutors We wish to ensure academic portability that is to ensure that the software will not b
16. e tied to teaching methodologies prevalent in a particular subject area The needs of different teachers might fall anywhere between the two extremes mentioned above i e rigidly structured computer based tutorials as favoured in many computer based teaching programmes in the hard sciences and particularly in law and the medical sciences and e the opportunity for free or only loosely constrained exploration of a large database of visual textual and numerical information as is epitomised by the BBC Domesday system and generally favoured in the social sciences and humanities We also wish to include facilities to record the progress of students both for the purposes of assessing individual students and for evaluating the general success or otherwise of the system as a whole or of particular strategies adopted by a tutor in different teaching contexts 37 9 Deliverables The deliverables from the Leicester project will be a mastered pilot videodisc the associated database and the control software Copies of the disc will be available at cost price and the database and control software free within British universities The pilot system is intended to provide a manageably sized demonstration of the potential of interactive videodiscs in teaching archaeology as well as a working resource relevant to the needs of undergraduate Archaeology students The subject area chosen for the pilot disc is prehistoric British ritual site
17. efact numbers and locations from a database being superimposed on a full colour photograph of an area under excavation an individual find could then be selected from the screen and displayed possibly as seen from any of several different angles along with any associated notes Interactive video has a huge potential for training purposes which has been recog nised for some time in industry and is gradually becoming exploited in secondary and higher education despite the high cost of actually mastering a videodisc The technol ogy is ideal for independent student use or with networked workstations sharing a single resource for tutorial group teaching Department of Computing Studies University of Leicester University Leicester LE 7RH 523 CLIVE RUGGLES For a background on the development of interactive videodisc technology the reader is referred to Martlew 1988 37 3 The software components of interactive videodisc systems Three software components can be identified in an interactive videodisc system The first and most obvious is an indexed collection of images The images are stored in analogue form on the videodisc as videodisc frames indexed by a unique frame number identifier The second component is a standard database of textual or numerical information This may also be held on the videodisc but can be held separately The database must be linked to the collection of images thus FrameID is a record type which will a
18. es tutorial files and student response files which are files created from time to time by tutors and students and are stored locally The images will be stored on each copy of the videodisc other software will be stored on computer media A 2 Organisation of the database 1 The database will be used to structure information pertinent to the subject theme and to relate this information to the videodisc images 2 The database will be set up using an off the shelf database management system dBa selll in the first instance 3 The database structure will be designed in a relational manner but implemented within the constraints of the database management system being used dBaselll for example does not support a fully relational structure but other systems which it is intended to use in later versions do do so 4 FrameID the index number of a frame on the videodisc will be a record type within the database 5 The detailed structure of the database will be described in the User Manual A 3 Physical organisation of videodisc frames 1 A videodisc will in general be organised by Chapters each containing frames relating to a distinct topic However the collection of frames on a topic can if desired span different chapters or different sides of a videodisc or even span more than one videodisc See also A 4 2 531 CLIVE RUGGLES 2 Some groups of frames hereinafter referred to as Movies
19. f the site At this point the user has two options e to exit from the Stonehenge item either back to the 1 50000 map from which it was selected by invoking Parent item on the Tree menu or back to the top level map by invoking Top item or e to progress to the next entry on Stonehenge by selecting Next entry on the Item menu The next entry on Stonehenge is a frame sequence When the entry is first selected the first plan in the sequence will be displayed The user may now move forwards or backwards at will through the sequence by invoking Next frame or Previous frame on the Sequence menu At any point in this process they may exit from the sequence either by moving to the next or previous entry on Stonehenge or by exiting the Stonehenge item altogether and going back to the maps If the sequence of Stonehenge plans is returned to at a later stage the first frame in the sequence the startup frame will again be displayed initially 542
20. ged but all frames in a grid must be accessible from all others Grids arise for example in the representation of geographical maps where neighbouring frames contain overlapping maps to the north south east and west of the current one In normal circumstances an abstract structure would be imposed upon the images on a videodisc or collection of videodiscs by the person who mastered the disc using our special configuration program To a tutor or student making subsequent use of the disc the abstract structure should be natural and need little extra thought the relationships between frames being suggested by the content of the frames themselves This is of course the case with the operations for moving to adjacent maps or zooming in or out on the Domesday system 37 15 Timescales The first deliverable product will be the videodisc which will be mastered in May 1988 Copies will be available shortly afterwards An intermediate version of the control software will be completed by the summer so that evaluation of the system can commence in the academic year 1988 89 Two workstations have been assembled in a room dedicated to the project in the Archaeology Department at Leicester University A further workstation is to be set up in the Department of Prehistory and Archaeology at the University of Sheffield The initial evaluation will take place at both locations An advanced version of the software will be available in March 1989 and will be
21. ided see Section A 4 4 is shown when a videodisc frame is displayed The default is captions shown 3 Mouse shortcuts off Mouse shortcuts on These disable enable the mouse shortcuts listed in A 9 5 below The default is mouse shortcuts on 4 Mouse shortcuts priority Pick area priority This sets the priority when a frame with pick areas is being displayed see A 9 6 below The default is pick area priority 5 Hide prompts Show prompts These determine whether the prompts generated by operations such as Subsidiary item and Measure area are shown The default is prompts shown AIBS Selecting a menu item from the Measure menu will have the following effects 1 Define units The user is prompted to name the measuring units being used the default is units Common units are recognised and their relationships to one another are known thus automatic conversions are possible 2 Define scales The user is prompted to draw a box on the screen This is done by clicking a mouse button with the cursor at the position of one corner and dragging the mouse to the Opposite corner where the button is released If the left button is used any rectangular box may be produced If the right button is used the box is constrained to be square The user is then prompted to indicate the length of the horizontal and vertical sides of the box in the current units 3 Measure line This option is only available if scales have been defined
22. isc the one which enables a student or tutor freely to browse the videodisc contents is described in more detail in Section A 9 37 12 Special features of the Leicester system Although the Leicester system is described in some detail in the Appendix we wish to draw attention here to two areas where our software aims to make significant advances over existing systems 37 13 Flexible authoring facilities Existing authoring tools as described above in Section 37 4 simply allow rigidly structured tutorials to be constructed by different tutors from a large databank of visual material Students running a particular tutorial are still subjected to a strict CAL methodology In order to ensure academic portability see Section 37 8 above we wish to cater for teaching methodologies between the extremes of strict CAL and completely unstruc tured exploration For example an archaeology tutor might wish to show the student some particular examples of prehistoric ritual sites in order to make a particular point about their architecture or design and then to allow the student to explore the database for similar sites viewing them or walking about them as much as desired in order to answer a more general question 527 CLIVE RUGGLES Suitably flexible authoring tools are contained in the Make Tutorial option see the Appendix Sections A 6 and A 8 Rigidly structured tutorials can be constructed by only displaying particular video
23. les a student or tutor to search the database freely Individual videodisc frames may be displayed during the course of such a search Also lists of frame numbers and their captions may be saved to files for future use in carousels or tutorials 3 Make carousel enables a user to prepare a carousel which is sequence of stills captioned or not as required by one of the following methods e constructing it from scratch constructing it from a list of frames generated by a database query or queries or e editing an existing carousel 4 View carousel enables a user to view a prepared carousel 935 CLIVE RUGGLES 5 Make tutorial enables a tutor to prepare a tutorial either by constructing it from scratch or by editing an existing one Carousels may provide the basis for information collection within a tutorial see A 6 3 above 6 Run tutorial enables a student to work through a prepared tutorial 7 Print enables a user to obtain a listing of the contents of a carousel or tutorial either on a printer or directed to a text file 8 Help gives access to information pertinent to operations 1 7 and their various sub operations structured accordingly 9 Quit exits the system and returns control to the operating system A 8 2 Within these options drop down menus will give access to various sub options All options will also be available by using the keyboard and they will often in addition be accessible by using the scree
24. may be organised in contiguous sequences on the disc The frames can then be sequentially displayed at the rate of 25 per second in order to produce a moving video film 3 The frames will also be organised according to an abstract structure described in Section A 4 below Where possible the physical organisation of these frames will reflect the abstract structure so as to give optimal access speeds 4 Other than as in 1 and 2 above and as may be possible as in 3 above the physical ordering of frames on a videodisc or videodiscs will be of no consequence A 4 Abstract organisation of videodisc frames A 4 1 An abstract videodisc consists of a number of frames linked by a structure whose general form is described below 1 An abstract videodisc consists of a number of ifems arranged in a tree structure An item consists of a list of entries and must contain at least one entry An entry is one of the following a grid a walkabout a movie a sequence or a single frame It contains a startup frame which is generally the frame displayed when the entry is first encountered 2 A grid is a collection of frames conceptually organised in a rectangular grid each frame having up to eight neighbours in the directions up left up and left etc The edge of a grid may be ragged but all frames in a grid must be accessible from all others Grids arise for example in the representation of geographical maps where neighbouring frames contain adjace
25. n cursor and mouse The left hand drop down menu will give access to other top level operations available from within the current one see A 8 3 below together with Exit to WP exit to word processor when it is available see A 8 4 below Help see A 8 5 below and Quit which will return the user to the operation from which the current one was called A 8 3 Some of the top level operations are available from within others Thus Browse videodisc and Browse database may be called from within Make carousel Make tutorial or Run tutorial View carousel may be called from within Make carousel Run tutorial may be called from within Make tutorial and Print may be called from within Make carousel or Make tutorial The available structure is illustrated by the following 58 ras vc ye aN BV amp BD A 8 4 Exit to WP is an option which enables the user to exit from the system and edit a document using a word processor When the user quits from the word processor action is resumed within the system from the point of departure Exit to WP is available within Browse videodisc Make carousel and Make tutorial It may also be inserted within a tutorial when a longer text response see A 6 4 above is required However a tutor must appreciate that the use of this facility results in a loss of security it being possible for a student to access the filestore and operating system from within many word processors 536 A LIVE PROJECT DRAF
26. no action will result when the relevant mouse button is clicked A 9 6 When the current frame has pick areas there is a potential clash between the ways of invoking operations using the cursor and mouse shortcuts listed in A 9 5 above and the way of calling up subsidiary frames directly using the pick areas see A 9 3 2 1 The toggling options Mouse shortcuts on Mouse shortcuts off and Mouse shortcuts priority Pick area priority allow this clash to be resolved in a way suitable to the user If mouse shortcuts are disabled then no clash arises If however mouse shortcuts are enabled as is the default then the situation is as follows When pick area priority is set see A 9 3 4 4 above as is the default the pick areas associated with the frame override the shortcut response areas Areas outside pick areas continue to function as response areas However if mouse shortcuts priority is set the pick areas may only be selected by explicitly invoking Select subsidiary item using the drop down menu mouse shortcuts see A 9 5 2 or keyboard The current situation will be obvious to the user because of the cursor icon see A 9 3 2 1 and A 9 5 541 CLIVE RUGGLES A 9 7 Example A 9 7 1 Configuration Suppose that a videodisc contains map coverage of Great Britain at three scales from one where the entire country fits into two frames down to 1 50000 as per the Domesday system It also contains pictorial information about v
27. nt or overlapping maps to the north south east and west of the current one 3 A walkabout is a collection of frames representing views as seen from a set of related positions They are organised so that neighbouring frames represent the views obtained by turning or moving to the left or right or by moving forwards or backwards Thus each frame has up to six neighbours The angle turned or the distance moved is flexible and may vary from frame to frame If sufficient neighbouring frames exist it will be possible to complete a panorama of views from a fixed spot by repeatedly turning to the left or right A map or plan may be available in order to show the current position and the possibilities for movement 4 A movie is a sequence of frames which can be run through to form a moving video film Facilities such as fast wind picture search forwards or backwards and freeze frame and frame stepping forwards and backwards are also provided The startup frame of a movie is the banner frame which is displayed until the movie is run When a movie has finished running the banner frame is displayed again 5 A sequence is a sequence of still frames which can only be stepped through manually The startup frame of a sequence is the first frame of the sequence 6 The startup frame of a single frame is the frame itself 7 An abstract videodisc contains a unique top item This item has no parent All other items have one and only one parent item and
28. op item First entry Browse Database Parent item Next entry Make Carousel Subsidiary item Previous entry View Carousel Make Tutorial Run Tutorial Print Exit to WP Help Quit 537 CLIVE RUGGLES Grid Walkabout Movie Sequence Startup frame Startup frame Banner frame First frame Move left Move forwards Run from start Next frame Move right Move backwards Run from here Previous frame Move up Turn left Fast forwards Move down Turn right Fast backwards Move up amp left Move left Freeze Move up amp right Move right Next frame Move down amp left Move left Previous frame Move down amp right Move right Options Measure Hide menus Define units Hide captions Show captions Define scales Mouse shortcuts off Mouse shortcuts on Measure area Mouse shortcuts priority Pick area priority Measure line Hide prompts Show prompts Square brackets indicate permanently unavailable options indicates toggling options There is no drop down menu corresponding to the SingleFrame header A 9 3 2 Selecting a menu item from the Tree Item Grid Walkabout or Sequence menus will simply cause a new videodisc frame to be shown except in the case of the following 1 Subsidiary item A message select relevant area or click both mouse buttons to abandon will be displayed Note that the relevant pick areas see Part II Section A 4 1 8 above may or may not be marked on the videodisc frame The relevant subsidiary item
29. ppear in relationships forming part of the database structure see Richards amp Ryan 1985 p 165 The final component is the control software which enables a user to explore and retrieve information in the database and to display selected images 37 4 The use of interactive video in training teaching methodologies Many systems used for industrial management training comprise a videodisc consisting mainly if not exclusively of moving sequences together with a program which takes the user a student on a learning path through them At various points the student is asked a question future progress depends on the response While different students will progress in different ways their progress will depend only upon their responses and the wishes of the original programmer This rigidly structured approach reflects the sort of methodology prevalent in many early computer aided learning CAL programmes in disciplines where an accumula tion of factual information is especially important such as law and the medical sciences The philosophy of the well known BBC Domesday system is very different Here the emphasis is upon allowing the user total freedom to investigate and interact with the visual information and the associated database There are no questions to be answered instead a student learns by exploring although this might well be done under tutorial guidance and certain goals might be set by the tutor A third approach is provi
30. s The first version of the pilot system will run on RM Nimbus PC1 workstations with Phillips videodisc players Subsequent versions will run on IBM compatible machines using other players In order to make use of the database features within the first version of the pilot system users will need to possess the dBaselll package Subsequent versions will offer alternatives In order to make use of the longer response capability see Appendix Section A 6 4 users will need to possess a suitable word processing package such as Microsoft Word or WordStar 37 10 Software development The author and two Computer Officers within the Department of Computing Studies at Leicester are involved in the software development for the project In addition a group of second year Computing Studies students have been set the design and development of part of the software a part which it is not essential to have in completed form by mid 1988 as a group project Software development methodologies taught to Computing Studies students have been used throughout in particular the progression from requirements to specification 526 OF SOFTWARE FOR THE LEICESTER INTERACTIVE VIDEODISC PROJECT design implementation and finally building and testing Requirements documents were produced within the Department of Archaeology and the Specification document progressing from an overall level to more detailed levels prepared in response within the Department of
31. sponse areas is shown below Entry Tree Item The relative proportions of these areas are not specified precisely They will be identifiable by the user by the fact that the mouse cursor will change form as it passes from one area to another A 9 5 2 When moved into the Tree area the cursor will change to a Tree icon The mouse options will then be as follows e Parent item Left click e Subsidiary item Right click Note that this results in the display of a message see A 9 3 2 1 above e Top item Double click If an entry is unavailable no action will result when the relevant mouse button is clicked A 9 5 3 When moved into the Item area the cursor will change to an Item icon The mouse options will then be as follows e Previous entry Left click e Next entry Right click e First entry Double click If an entry is unavailable no action will result when the relevant mouse button is clicked A 9 5 4 The form of the mouse cursor in the Entry area will depend upon the nature of the current entry grid walkabout etc and upon the screen position For example if the cursor is moved to the right hand side of the screen when the current entry is a grid it will change to a right facing arrow icon indicating that if the mouse button is clicked in this position Move right will result Unavailable options such as Move right in a grid when no right move is possible from the current frame will be indic
32. ted free browse and response without structuring the student s progress in any way AO 2 A tutorial consists of videodisc frames text information and prompts and mechanisms for obtaining student input in various forms Many paths through a tutorial will in general be possible A 6 3 A tutorial may be viewed as a network of nodes where interaction takes place connected by paths The interaction at a node may consist of the collection of information by a student and or their response to a particular problem When a response has been elicited the path followed after leaving the node may depend upon the response The level of constraint in the process of information collection and response is determined by the tutor A 6 4 One of four forms of student response may be elicited at a node 1 A choice i e the selection of one of a number of options offered as in a multiple choice question The subsequent path will in general depend upon the option chosen 2 A screen position The subsequent path will in general depend upon which if any of a number of pick areas the given position lies within 534 A LIVE PROJECT DRAFT SYSTEM SPECIFICATION 3 A single line up to 80 characters of text The subsequent path will in general depend upon the presence or absence of certain character strings within the line of text 4 A longer piece of text There is no choice of subsequent path Student responses of types 1 3 will au
33. tomatically be logged by the system and stored in a student response log file see Section A 7 below Responses of type 4 will be obtained by allowing the student to use a suitable word processor and will be stored in a student response document file A 6 5 Information about a tutorial is stored in a tutorial file which when loaded by the user within the system enables a tutorial to be run or edited Safeguards are incorporated in order to prevent misuse of the system by students A 6 6 A student may save their current position within a tutorial and resume later A 7 Structure of a student response file A student response log file contains 1 A report on responses of types 1 3 see A 6 4 above This is in a form which facilitates marking by the tutor 2 A report on the student s path through the tutorial This is in a form which facilitates analysis for the purposes of evaluation Part Il OPERATIONS A 8 Top level operations A 8 The following nine options will be available upon entry to the system Browse videodisc Browse database Make carousel View carousel Make tutorial Run tutorial Print Help and Quit These operations will be invoked from a display screen by clicking the mouse in suitable response areas 1 Browse videodisc enables a student or tutor to browse the videodisc freely Default captions see Section A 4 4 are displayed wherever they are provided 2 Browse database enab
34. will be selected by clicking either mouse button with the cursor within a pick area The operation is terminated if the mouse is double clicked regardless of the cursor position The relevant subsidiary item may also be selected simply by clicking either mouse button with the cursor within a pick area thus short cutting the drop down menu depending on the option settings see A 9 6 below When the cursor is within an active pick area it changes to a Pick area icon 2 Show map The walkabout frame will be replaced by a map which might either be a videodisc frame itself overlaid by computer graphics or entirely graphics generated The current position and orientation will be indicated A box labelled resume will be displayed When either mouse button is clicked with the cursor within the box the interrupted walkabout frame will be re displayed A933 Selecting a menu item from the Movie menu will either cause a moving frame sequence or a still frame to be displayed see Section A 4 1 4 A 9 3 4 Selecting a menu item from the Options menu will have the following effects 1 Hide menus The drop down menus will disappear A small area will become available which when the cursor is positioned within it and either mouse button clicked will restore the drop down menus 538 A LIVE PROJECT DRAFT SYSTEM SPECIFICATION 2 Hide captions Show captions These determine whether the default caption wherever one is prov
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