The star user interface: an overview
Contents
1. village just as the Arpanet has brought computer science researchers around the world closer together This may be the most profound impact that computers have on society Calculator A variety of styles of calculators Figure 12 let you perform arithmetic calculations Numbers can be moved between Star documents and calculators thereby reducing the amount of typing and the possibility of errors Rows or columns of tables can be summed The calculators are user tailorable and exten sible Most are modeled after pocket calculators business scientific four function but one is a tabular calculator simi lar to the popular Visicalc program x is rt oe DE E a ae oe 7 hE ee nae Figure 12 A calculator icon Terminal emulators The terminal emulators permit you to communicate with existing mainframe computers using existing protocols Ini tially teletype and 3270 terminals are emulated with addi tional ones later Figure 13 You open one of the terminal icons and type into its window the contents of the window behave exactly as if you were typing at the corresponding terminal Text in the window can be copied to and from Star documents which makes Star s rich environment available to them Figure 13 3270 and TTY emulation icons Directory The Directory provides access to network resources It serves as the source for icons representing those resources the Directory contains one icon for ea2. This was acceptable and even desirable in a research environment producing experimental software But it presented the Star designers with the challenge of syn thesizing the various interfaces into a single coherent uni form one ESSENTIAL HARDWARE Before describing Star s user interface we should point out that there are several aspects of the Star and Alto architec ture that are essential to it Without these elements it would have been impossible to design a user interface anything like the present one Display Both Star and Alto devote a portion of main memory to the bit mapped display screen 100K bytes in Star 50K bytes usually in Alto Every screen dot can be individually turned on or off by setting or resetting the corresponding bit in memory This gives both systems substantial ability to portray graphic images From the collection of the Computer History Museum www computerhistory org 518 National Computer Conference 1982 Memory Bandwidth Both Star and Alto have a high memory bandwidth about 50 MHz in Star The entire Star screen is repainted from memory 39 times per second This 50 MHz video rate would swamp most computer memories and in fact refreshing the screen takes about 60 of the Alto s memory bandwidth However Star s memory is double ported therefore refresh ing the display does not appreciably slow down CPU memory access Star also has separate logic devoted solely to refres
3. the contents in the case of a document window they go to the next or previous page Finally the vertical scroll bar has a jumping area for going to a particular part of the contents such as to a particular page in a document Unlike the windows in some Alto programs Star windows do not overlap This is a deliberate decision based on our observation that many Alto users were spending an inordinate amount of time manipulating windows themselves rather than their contents This manipulation of the medium is overhead and we want to reduce it Star automatically partitions the display space among the currently open windows You can control on which side of the screen a window appears and its height PROPERTY SHEETS At a finer grain the Star world is organized in terms of objects that have properties and upon which actions are performed A few examples of objects in Star are text characters text para graphs graphic lines graphic illustrations mathematical sum mation signs mathematical formulas and icons Every object has properties Properties of text characters include type style size face and posture e g bold italic Properties of paragraphs include indentation leading and alignment Properties of graphic lines include thickness and structure e g solid dashed dotted Properties of document icons include name size creator and creation date So the proper ties of an object depend on the type of the object These id
4. 1982 MOVE also reinforces Star s physical metaphor a moved object can be in only one place at one time Most computer file transfer programs only make copies they leave the origi nals behind Although this is an admirable attempt to keep information from accidentally getting lost an unfortunate side effect is that sometimes you lose track of where the most recent information is since there are multiple copies floating around MOVE lets you model the way you manipulate infor mation in the real world should you wish to We expect that during the creation of information people will primarily use MOVE during the dissemination of information people will make extensive use of COPY Copy COPY is just like MOVE except that it leaves the original object behind untouched Star elevates the concept of copying to the level of a paradigm for creating In all the various domains of Star you create by copying Creating something out of nothing is a difficult task Everyone has observed that it is easier to modify an existing document or program than to write it originally Picasso once said The most awful thing for a painter is the white canvas To copy others is neces sary Star makes a serious attempt to alleviate the problem of the white canvas to make copying a practical aid to creation Consider You create new documents by copying existing ones Typically you set up blank documents with appropriate format
5. is a text parameter for the string to search for a choice parameter for the range over which to search and a state parameter CHANGE IT controlling whether to replace that string with another one When CHANGE IT is turned on an additional set of parameters appears to contain the replacement text This technique of having some parameters appear depending on the settings of others is another part of our strategy of progressive disclo sure hiding information and therefore complexity until it is From the collection of the Computer History Museum www computerhistory org The Star User Interface An Overview 525 needed but making it visible when it is needed The various sheets appear simpler than if all the options were always shown COMMANDS Commands in Star take the form of noun verb pairs You specify the object of interest the noun and then invoke a command to manipulate it the verb Specifying an object is called making a selection Star provides powerful selection mechanisms which reduce the number and complexity of commands in the system Typically you exercise more dexter ity and judgment in making a selection than in invoking a command The ways to make a selection are as follows 1 With the mouse Place the cursor over the object on the screen you want to select and click the first SELECT mouse button Additional objects can be selected by using the second ADJUST mouse button it adjusts the selection to i
6. just as in real life You can leave documents on your Desktop indefinitely just as on a real desk or you can file them away ICONS An icon is a pictorial representation of a Star object that can exist on the Desktop On the Desktop the size of an icon is approximately 1 inch square Inside a window such as a folder window the size of an icon is approximately 14 inch square Iconic images have played a role in human communication from cave paintings in prehistoric times to Egyptian hiero glyphics to religious symbols to modern corporate logos Computer science has been slow to exploit the potential of visual imagery for presenting information particularly ab _ Stract information Among the reasons are the lack of development of appropriate hardware and software for pro ducing visual imagery easily and inexpensively computer technology has been dominated by persons who seem to be happy with a simple very limited alphabet of characters used to produce linear strings of symbols One of the authors has applied icons to an environment for writing programs he found that they greatly facilitated human computer commu nication Negroponte s Spatial Data Management system has effectively used iconic images in a research setting And there have been other efforts But Star is the first com puter system designed for a mass market to employ icons methodically in its user interface We do not claim that Star exploit
7. The star user interface an overview by DAVID CANFIELD SMITH CHARLES IRBY and RALPH KIMBALL Xerox Corporation Palo Alto California and ERIC HARSLEM Xerox Corporation El Segundo California ABSTRACT In April 1981 Xerox announced the 8010 Star Information System a new personal computer designed for office professionals who create analyze and distribute information The Star user interface differs from that of other office computer systems by its emphasis on graphics its adherence to a metaphor of a physical office and its rigorous application of a small set of design principles The graphic imagery reduces the amount of typing and remembering required to operate the system The office metaphor makes the system seem familiar and friendly it reduc es the alien feel that many computer systems have The design principles unify the nearly two dozen functional areas of Star increasing the coherence of the system and allowing user experience in one area to apply in others 515 From the collection of the Computer History Museum www computerhistory org From the collection of the Computer History Museum www computerhistory org The Star User Interface An Overview 517 INTRODUCTION In this paper we present the features in the Star system with out justifying them in detail In a companion paper we dis cuss the rationale for the design decisions made in Star We assume that the reader has a general familiarity wit
8. ch Center 1976 and 1978 Much of the design and all of the imple mentation of Bravo was done by Charles Simonyi and the skilled pro grammers in his software factory Baudelaire P and M Stone Techniques for Interactive Raster Graph ics Proceedings of the 1980 Siggraph Conference 14 1980 3 Tesler L The Smalltalk Environment Byte 6 1981 pp 90 147 Wertenbaker L The World of Picasso New York Time Life Books 1967 Bush V As We May Think Atlantic Monthly July 1945 Engelbart D C Augmenting Human Intellect A Conceptual Frame work Technical Report AFOSR 3223 SRI International Menlo Park Calif 1962 Engelbart D C and W K English A Research Center for Augmenting Human Intellect AFIPS Proceedings of the Fall Joint Computer Confer ence Vol 33 1968 pp 395 410 From the collection of the Computer History Museum www computerhistory org
9. ch resource available Figure 14 When you are first registered in a Star network From the collection of the Computer History Museum www computerhistory org The Star User Interface An Overview 523 Figure 14 A Directory icon your Desktop contains nothing but a Directory icon From this initial state you access resources such as file drawers printers and mail baskets by opening the Directory and copy ing out their icons You can also get blank data icons out of the Directory You can retrieve other data icons from file draw ers Star places no limits on the complexity of your Desktop except the limitation imposed by physical screen area Figure 15 The Directory also contains Remote Directories repre senting resources available on other networks These can be opened recursively and their resource icons copied out just as with the local Directory You deal with local and remote resources in exactly the same way Figure 15 The Directory window showing the categories of resources available The important thing to observe is that although the func tions performed by the various icons differ the way you inter act with them is the same You select them with the mouse You push the MOVE COPY or DELETE key You push the OPEN key to see their contents the PROPERTIES key to see their properties and the SAME key to copy their properties This is the result of rigorously applying the principle of uni formity to the d
10. contents of file drawers can be shared by multiple users File drawers have associated access rights to control the ability of people to look at and modify their contents Figure 6 Although the design of file drawers was motivated by their physical counterparts they are a good example of why it is neither necessary nor desirable to stop with just duplicating real world behavior People have a lot of trouble finding things in filing cabinets Their categorization schemes are fre quently ad hoc and idiosyncratic If the person who did the categorizing leaves the company information may be per manently lost Star improves on physical filing cabinets by taking advantage of the computer s ability to search rapidly You can search the contents of a file drawer for an object having a certain name or author or creation date or size or a variety of other attributes The search criteria can use fuzzy patterns containing match anything symbols ranges and other predicates You can also sort the contents on the basis of those criteria The point is that whatever information re trieval facilities are available in a system should be applied to ON OR aed 148 Baers 10 CS Marmo Farry 4 Page HRUB me fAigeipnaen S Guies Hi paper g materiai Oi Gun ME 18 85 Figure 6 An open file drawer window Note that there is a miniature icon for each object inside the file drawer From the collection of the Computer History Museum www c
11. d pioneered by Doug Engelbart in his NLS system The interconnections permit cross referencing without duplication The SEARCH FOR KEYWORD command tThis com mand in the Help window menu lets you search the avail able documentation for information on a specific topic The keywords are predefined by the writers of the Help material Figure 20 The Help window showing the table of contents Selecting a square with a question mark in it takes you to the associated part of the Help documentation SUMMARY We have learned from Star the importance of formulating the user s conceptual model first before software is written rath er than tacking on a user interface afterward Doing good user interface design is not easy Xerox devoted about thirty work years to the design of the Star user interface It was designed before the functionality of the system was fully decided It was designed before the computer hardware was even built We worked for two years before we wrote a single line of actual product software Jonathan Seybold put it this way Most system design efforts start with hardware specifications fol low this with a set of functional specifications for the software then try to figure out a logical user interface and command structure The Star project started the other way around the paramount concern was to define a conceptual model of how the user would relate to the system Hardware and software followed
12. e organization A person s linear name need be unique only within his division It can be fully spelled out if necessary including spaces and punctuation Aliases can be defined User icons are references to this information You need not even know let alone type the unique linear repre sentation for a user you need only have the icon User group User group icons Figure 11 contain individual users and or other user groups They allow you to organize people ac cording to various criteria User groups serve both to control ats KALA EE t a 8 KAS sy pe ee SE DEG a y x ED 9 aat i 7 k atat f tay ata Ba a 4G KJ whet fS EAE ZE f re ae hag P E a FE E d E AE a EE E E E oe Eee ew ee ee ee a oe es Figure 11 A user group icon access to information such as file drawers access control lists and to make it easy to send mail to a large number of people distribution lists The latter is becoming increasingly im portant as more and more people start to take advantage of computer assisted communication At Xerox we have found that as soon as there were more than a thousand Alto users there were almost always enough people interested in any topic whatsoever to form a distribution list for it These user groups have broken the bonds of geographical proximity that have historically limited group membership and commu nication They have begun to turn Xerox into a nationwide
13. e system in a variety of formats e g Xerox 860 IBM OS6 but they can be edited only in Star format Conversion operations are provided to translate between the various formats Folder A folder is used to group data icons together It can contain documents record files and other folders Folders can be nested inside folders to any level Like file drawers see be low folders can be sorted and searched Record file A record file is a collection of information organized as a set of records Frequently this information will be the variable data from forms These records may be sorted subset via pattern matching and formatted into reports Record files provide a rich set of information storage and retrieval functions Function Icons Function icons represent objects that perform actions Most function icons will operate on any data icon There are many kinds of function icons with more being added as the system evolves File drawer A file drawer Figure 5 is a place to store data icons It is modeled after the drawers in office filing cabinets The or ganization of a file drawer is up to you it can vary from a simple list of documents to a multilevel hierarchy of folders Figure 5 A file drawer icon containing other folders File drawers are distinguished from other storage places folders floppy disks and the Desktop in that 1 icons placed in a file drawer are physically stored on a file server and 2 the
14. eas are similar to the notions of classes objects and messages in Simula and Smalltalk Among the editors that use these ideas are the experimental text editor Bravo and the experi mental graphics editor Draw both developed at the Xerox Palo Alto Research Center These all supplied valuable knowledge and insight to Star In fact the text editor aspects of Star were derived from Bravo In order to make properties visible we invented the notion of a property sheet Figure 16 A property sheet is a two dimensional formlike environment which shows the proper From the collection of the Computer History Museum www computerhistory org 524 National Computer Conference 1982 Figure 16 The property sheet for text characters ties of an object To display one you select the object of interest using the mouse and push the PROPERTIES key on the keyboard Property sheets may contain three types of parameters 1 State State parameters display an independent proper ty which may be either on or off You turn it on or off by pointing to it with the mouse and clicking a mouse button When on the parameter is shown video re versed In general any combination of state parameters in a property sheet can be on If several state parameters are logically related they are shown on the same line with space between them See Face in Figure 16 Choice Choice parameters display a set of mutually exclusive values for a pro
15. esign of icons We have applied it to other areas of Star as well as will be seen WINDOWS Windows are rectangular areas that display the contents of icons on the screen Much of the inspiration for Star s design came from Alan Kay s Flex machine and his later Smalltalk programming environment on the Alto The Officetalk treatment of windows was also influential in fact Officetalk an experimental office forms processing system on the Alto provided ideas in a variety of areas Windows greatly in crease the amount of information that can be manipulated on a display screen Up to six windows at a time can be open in Star Each window has a header containing the name of the icon and a menu of commands The commands consist of a standard set present in all windows CLOSE SET WIN DOW and others that depend on the type of icon For exam ple the window for a record file contains commands tailored to information retrieval CLOSE removes the window from the display screen returning the icon to its tiny size The command displays the online documentation describing the type of window and its applications Each window has two scroll bars for scrolling the contents vertically and horizontally The scroll bars have jump to end areas for quickly going to the top bottom left or right end of the contents The vertical scroll bar also has areas labeled N and P for quickly getting the next or previous screenful of
16. eted by pushing the MOVE COPY or DE LETE key on the keyboard Moving a document is the elec tronic equivalent of picking up a piece of paper and walking somewhere with it To file a document you move it to a picture of a file drawer just as you take a piece of paper to a physical filing cabinet To print a document you move it to a picture of a printer just as you take a piece of paper to a copying machine Though we want an analogy with the physical world for familiarity we don t want to limit ourselves to its capabilities One of the raisons d tre for Star is that physical objects do not provide people with enough power to manage the increasing complexity of their information For example we can take advantage of the computer s ability to search rapidly by pro viding a search function for its electronic file drawers thus helping to solve the problem of lost files THE DESKTOP Every user s initial view of Star is the Desktop which resem bles the top of an office desk together with surrounding fur niture and equipment It represents a working environment where current projects and accessible resources reside On the screen Figure 3 are displayed pictures of familiar office ob jects such as documents folders file drawers in baskets and out baskets These objects are displayed as small pictures or icons You can open an icon by selecting it and pushing the OPEN key on the keyboard When opened an icon ex
17. from this Alto served as a valuable prototype for Star Over a thou sand Altos were eventually built and Alto users have had several thousand work years of experience with them over a period of eight years making Alto perhaps the largest proto From the collection of the Computer History Museum www computerhistory org 528 National Computer Conference 1982 typing effort in history There were dozens of experimental programs written for the Alto by members of the Xerox Palo Alto Research Center Without the creative ideas of the au thors of those systems Star in its present form would have been impossible On the other hand it was a real challenge to aah SAGARA 4 bring some order to the different user interfaces on the Alto In addition we ourselves programmed various aspects of the Star design on Alto but every bit sic of it was throwaway code Alto with its bit mapped display screen was powerful enough to implement and test our ideas on visual interaction REFERENCES 1 Smith D C E F Harslem C H Irby R B Kimball and W L Verplank Designing the Star User Interface Byte April 1982 2 Metcalfe R M and D R Boggs Ethernet Distributed Packet Switch ing for Local Computer Networks Communications of the ACM 19 1976 pp 395 404 3 Intel Digital Equipment and Xerox Corporations The Ethernet A Lo cal Area Network Data Link Layer and Physical Layer Specifications vers
18. h ing the display Microcoded Personal Computer Both Star and Alto are personal computers one user per machine Therefore the needed memory access and CPU cy cles are consistently available Special microcode has been written to assist in changing the contents of memory quickly permitting a variety of screen processing that would otherwise not be practical Mouse Both Star and the Alto use a pointing device called the mouse Figure 2 First developed at SRI Xerox s version has a ball on the bottom that turns as the mouse slides over a flat surface such as a table Electronics sense the ball rotation and guide a cursor on the screen in corresponding motions The mouse is a Fitts s law device that is after some practice Figure 2 The Star keyboard and mouse The keyboard has 24 easy to understand function keys The mouse has two buttons on top you can point with a mouse as quickly and easily as you can with the tip of your finger The limitations on pointing speed are those inherent in the human nervous system The mouse has buttons on top that can be sensed under program control eh The buttons let you point to and interact with objects on the screen in a variety of ways Local Disk Every Star and Alto has its own rigid disk for local storage of programs and data Editing does not require using the network This enhances the personal nature of the machines any o other well nt m xy maii
19. h computer text editors but no familiarity with Star The Star hardware consists of a processor a two page wide bit mapped display a keyboard and a cursor control device The Star software addresses about two dozen functional areas of the office encompassing document creation data pro cessing and electronic filing mailing and printing Docu ment creation includes text editing and formatting graphics editing mathematical formula editing and page layout Data processing deals with homogeneous databases that can be sorted filtered and formatted under user control Filing is an example of a network service using the Ethernet local area network Files may be stored on a work station s disk Fig ure 1 on a file server on the work station s network or on a file server on a different network Mailing permits users of work stations to communicate with one another Printing uses laser driven xerographic printers capable of printing both text and graphics The term Star refers to the total system hard ware plus software As Jonathan Seybold has written This is a very different product Different because it truly bridges word processing Figure 1 A Star workstation showing the processor display keyboard and mouse and typesetting functions different because it has a broader range of capabilities than anything which has preceded it and different because it introduces to the commercial market rad ically new concepts i
20. hat can be created on the screen Low cost typewriter based printers are also available these can render only text As with filing and mailing the existence of the Ethernet greatly enhances the power of printing The printer repre sented by an icon on your Desktop can be in the same room as your work station in a different room in a different build SPR Re RS ft y ae a Pure Figure 8 A printer icon ing in a different city even in a different country You per form exactly the same actions to print on any of them Select a data icon push the MOVE key and indicate the printer icon as the destination Floppy disk drive The floppy disk drive icon Figure 9 allows you to move data icons to and from a floppy disk inserted in the machine This provides a way to store documents record files and fold ers Off line When you open the floppy disk drive icon Star reads the floppy disk and displays its contents in the window Its window looks and acts just like a folder window icons may be moved or copied in or out or deleted The only difference is the physical location of the data Figure 9 A floppy disk drive icon User The user icon Figure 10 displays the information that the system knows about each user name location password invisible of course aliases if any home file and mail serv ers access level ordinary user system administrator help training writer and so on We expect the information s
21. ion 1 0 Palo Alto Xerox Office Products Division 1980 4 Seybold J W Xerox s Star The Seybold Report Media Pennsyl vania Seybold Publications 10 1981 16 5 Thacker C P E M McCreight B W Lampson R F Sproull and D R Boggs Alto A Personal Computer In D Siewiorek C G Bell and A Newell eds Computer Structures Principles and Examples New York McGraw Hill 1982 6 Ingalls D H The Smalltalk Graphics Kernel Byte 6 1981 pp 168 194 7 English W K D C Engelbart and M L Berman Display Selection Techniques for Text Manipulation IEEE Transactions on Human Factors in Electronics HFE 8 1967 pp 21 31 8 Fitts P M The Information Capacity of the Human Motor System in Controlling Amplitude of Movement Journal of Experimental Psy chology 47 1954 pp 381 391 9 Card S W K English and B Burr Evaluation of Mouse Rate Controlled Isometric Joystick Step Keys and Text Keys for Text Selection on a CRT Ergonomics 21 1978 pp 601 613 10 11 12 13 15 16 17 18 19 20 21 22 23 24 25 26 27 Oppen D C and Y K Dalal The Clearinghouse A Decentralized Agent for Locating Named Objects in a Distributed Environment Palo Alto Xerox Office Products Division OPD T8193 1981 Huggins W H and D Entwisle Iconic Communication Baltimore and London The John
22. m commands since invoking the command is the last step Inserting text does not require a command you simply make a selection and begin typing The text is placed after the end of the selection A few commands require more than one operand and hence are modal For example the MOVE and COPY commands require a destination as well as a source GENERIC COMMANDS Star has a few commands that can be used throughout the system MOVE COPY DELETE SHOW PROPERTIES COPY PROPERTIES AGAIN UNDO and HELP Each performs the same way regardless of the type of object se lected Thus we call them generic commands For example you follow the same set of actions to move text in a document as to move a document in a folder or a line in an illustration select the object move the MOVE key and indicate the destination Each generic command has a key devoted to it on the keyboard HELP and UNDO don t use a selection These commands are more basic than the ones in other computer systems They strip away extraneous application specific semantics to get at the underlying principles Star s generic commands are derived from fundamental computer science concepts because they also underlie operations in pro gramming languages For example program manipulation of data structures involves moving or copying values from one data structure to another Since Star s generic commands em body fundamental underlying concepts they are widely appli cable Each c
23. m keyboard windows Since there are many more characters up to 2 6 in the Star character set than there are keys on the keyboard Star provides a series of key board interpretation windows Figure 19 which allow you to see and change the meanings of the keyboard keys You are presented with the options you iook them over and choose the ones you want Figure 19 The Keyboard Interpretation window This displays other characters that may be entered from the keyboard The character set shown here contains a variety of common office symbols Delete This deletes the selected object If you delete something by mistake UNDO will restore it Show Properties SHOW PROPERTIES displays the properties of the se lected object in a property sheet You select the object s of interest push the PROPERTIES PROP S key and the ap propriate property sheet appears on the screen in such a pos ition as to not overlie the selection if possible You may change as many properties as you wish including none When finished you invoke the Done command in the property sheet menu The property changes are applied to the selected ob jects and the property sheet disappears Notice that SHOW PROPERTIES is therefore used both to examine the current properties of an object and to change those properties Copy Properties You need not use property sheets to alter properties if there is another object on the screen that already has the desired
24. n human engineering The Star hardware was modeled after the experimental Alto computer developed at the Xerox Palo Alto Research Center Like Alto Star consists of a Xerox developed high bandwidth MSI processor local disk storage a bit mapped display screen having a 72 dot per inch resolution a pointing device called the mouse and a connection to the Ethernet Stars are higher performance machines than Altos being about three times as fast having 512K bytes of main memory vs 256K bytes on most Altos 10 or 29M bytes of disk memory vs 2 5M bytes a 10 2 by 13 2 inch display screen vs a 10 2 by 82 inch one 1024 x 808 addressable screen dots vs 606 x 808 and a 10M bits per second Ethernet vs 3M bits Typically Stars like Altos are linked via Ethernets to each other and to shared file mail and print servers Com munication servers connect Ethernets to one another either directly or over phone lines enabling internetwork commu nication to take place This means for example that from the user s perspective it is no harder to retrieve a file from a file server across the country than from a local one Unlike the Alto however the Star user interface was de signed before the hardware or software was built Alto soft ware of which there was eventually a large amount was de veloped by independent research teams and individuals There was little or no coordination among projects as each pursued its own goals
25. nclude more or fewer objects Most selec tions are made in this way 2 With the NEXT key on the keyboard Push the NEXT key and the system will select the contents of the next field in a document Fields are one of the types of special higher level objects that can be placed in documents If the selection is currently in a table NEXT will step through the rows and columns of the table making it easy to fill in and modify them If the selection is cur rently in a mathematical formula NEXT will step through the various elements in the formula making it easy to edit them NEXT is like an intelligent step key it moves the selection between semantically meaningful locations in a document 3 With a command Invoke the FIND command and the system will select the next occurrence of the specified text if there is one Other commands that make a selec tion include OPEN the first object in the opened win dow is selected and CLOSE the icon that was closed becomes selected These optimize the use of the system Figure 18 The Find option sheet showing Substitute options The extra options appear only when CHANGE IT is turned on The object noun is almost always specified before the action verb to be performed This makes the command in terface modeless you can change your mind as to which object to affect simply by changing the selection before invoking the command No accept function is needed to terminate or confir
26. ommand fills a host of needs Few commands are required This simplicity is desirable in itself but it has anoth er subtle advantage it makes it easy for users to form a model of the system What people can understand they can use Just as progress in science derives from simple clear theories so progress in the usability of computers depends on simple clear user interfaces Move MOVE is the most powerful command in the system It is used during text editing to rearrange letters in a word words in a sentence sentences in a paragraph and paragraphs in a document It is used during graphics editing to move picture elements such as lines and rectangles around in an illustration It is used during formula editing to move mathematical struc tures such as summations and integrals around in an equation It replaces the conventional store file and retrieve file commands you simply move an icon into or out of a file drawer or folder It eliminates the send mail and receive mail commands you move an icon to an Out basket or from an In basket It replaces the print command you move an icon to a printer And so on MOVE strips away much of the historical clutter of computer commands It is more funda mental than the myriad of commands it replaces It is simulta neously more powerful and simpler From the collection of the Computer History Museum www computerhistory org 526 National Computer Conference
27. omputerhistory org The Star User Interface An Overview 521 the information in files Any system that does not do so is not exploiting the full potential of the computer In basket and Out basket These provide the principal mechanism for sending data icons to other peopie Figure 7 A data icon piaced in the Out basket will be sent over the Ethernet to a mail server usually the same machine as a file server thence to the mail servers of the recipients which may be the same as the sender s and thence to the In baskets of the recipients When you have mail waiting for you an envelope appears in your In basket icon When you open your In basket you can display and read the mail in the window Any document record file or folder can be mailed Docu ments need not be limited to plain text but can contain illus trations mathematical formulas and other nontext material Folders can contain any number of items Record files can be arbitrarily large and complex Figure 7 In and Out basket icons Printer Printer icons Figure 8 provide access to printing services The actual printer may be directly connected to your work station or it may be attached to a print server connected to an Ethernet You can have more than one printer icon on your Desktop providing access to a variety of printing resources Most printers are expected to be laser driven raster scan xero graphic machines these can render on paper anything t
28. our parameters there are over 8X 2x 2 x8 2048 combinations of character properties 2 They show all of the properties of an object None is hidden You are constantly reminded what is available every time you display a property sheet 3 They provide progressive disclosure There are a large number of properties in the system as a whole but you want to deal with only a small subset at any one time Only the properties of the selected object are shown 4 They provide a bullet proof environment for altering the characteristics of an object Since only the properties of the selected object are shown you can t accidentally alter other objects Since only valid choices are dis played you can t specify illegal properties This reduces errors Property sheets are an example of the Star design principle that seeing and pointing is preferred over remembering and typing You don t have to remember what properties are avail able for an object the property sheet will show them to you This reduces the burden on your memory which is particu larly important in a functionally rich system And most prop erties can be changed by a simple pointing action with the mouse The three types of parameters are also used in option sheets Figure 18 Option sheets are just like property sheets ex cept that they provide a visual interface for arguments to com mands instead of properties of objects For example in the Find option sheet there
29. pands into a larger form called a window which displays the icon s contents This enables you to read documents inspect the Figure 3 A Desktop as it appears on the Star screen This one has several commonly used icons along the top including documents to serve as form pad sources for letters memos and blank paper There is also an open window displaying a document contents of folders and file drawers see what mail has arrived and perform other activities Windows are the principal mech anism for displaying and manipulating information The Desktop surface is displayed as a distinctive grey pat tern This is restful and makes the icons and windows on it stand out crisply minimizing eye strain The surface is or ganized as an array of 1 inch squares 14 wide by 11 high An icon may be placed in any square giving a maximum of 154 icons Star centers an icon in its square making it easy to line up icons neatly The Desktop always occupies the entire dis play screen even when windows appear on the screen the Desktop continues to exist beneath them The Desktop is the principal Star technique for realizing the physical office metaphor The icons on it are visible concrete embodiments of the corresponding physical objects Star users are encouraged to think of the objects on the Desktop in physical terms You can move the icons around to arrange your Desktop as you wish Messy Desktops are certainly possible
30. perty Exactly one value must be on at all times As with state parameters you turn on a choice by pointing to it with the mouse and clicking a mouse button If you turn on a different value the sys tem turns off the previous one Again the one that is on is Shown video reversed See Font in Figure 16 The motivation for state and choice parameters is the obser vation that it is generally easier to take a multiple choice test than a fill in the blanks one When options are made visible they become easier to understand remem ber and use 3 Text Text parameters display a box into which you can type a value This provides a largely unconstrained choice space you may type any value you please within the limits of the system The disadvantage of this is that the set of possible values is not visible therefore Star uses text parameters only when that set is large See Search for in Figure 17 bo Property sheets have several important attributes 1 A small number of parameters gives you a large number of combinations of properties They permit a rich choice space without a lot of complexity For example the char acter property sheet alone provides for 8 fonts from 1 to 6 sizes for each an average of about 2 4 faces any Figure 17 The option sheet for the Find command combination of which can be on and 8 positions rela tive to the baseline including OTHER which lets you type in a value So in just f
31. properties You can select the object s to be changed push the SAME key then designate the object to use as the source COPY PROPERTIES makes the selection look the same as the source This is particularly useful in graphics editing Frequently you will have a collection of lines and symbols whose appearance you want to be coordinated all the same line width shade of grey etc You can seiect aii the objects to be changed push SAME and select a line or symbol having From the collection of the Computer History Museum www computerhistory org The Star User Interface An Overview 527 the desired appearance In fact we find it helpful to set up a document with a variety of graphic objects in a variety of appearances to be used as sources for copying properties Again AGAIN repeats the last command s on a new selection All the commands done since the last time a selection was made are repeated This is useful when a short sequence of commands needs to be done on several different selections for example make several scattered words bold and italic and in a larger font Undo UNDO reverses the effects of the last command It provides protection against mistakes making the system more forgiv ing and user friendly Only a few commands cannot be re peated or undone Help Our effort to make Star a personal self contained system goes beyond the hardware and software to the tools that Star provides to teach people ho
32. resulting i in consistent behavior regar aiess G UL il Ow ill machines there are on the network or what anyone else 1s doing Large programs can be written using the disk for swapping Network The Ethernet lets both Stars and Altos have a distributed architecture Each machine is connected to an Ethernet Other machines on the Ethernet are dedicated as servers machines that are attached to a resource and that provide access to that resource Typical servers are these 1 File server Sends and receives files over the network storing them on its disks A file server improves on a work station s rigid disk in several ways a Its capacity is greater up to 1 2 billion bytes b It provides backup facilities c It allows files to be shared among users Files on a work station s disk are inaccessible to anyone else on the network 2 Mail server Accepts files over the network and distrib utes them to other machines on behalf of users employ ing the Clearinghouse s database of names and ad dresses see below 3 Print server Accepts print format files over the net work and prints them on the printer connected to it 4 Communication server Provides several services The Clearinghouse service resolves symbolic names into net work addresses The Internetwork Routing service manages the routing of information between networks over phone lines The Gateway service allows word pro cessors and dumb terminals to acces
33. s Hopkins University Press 1974 Smith D C Pygmalion A Computer Program to Model and Stimulate Creative Thought Basel and Stuttgart Birkh user Verlag 1977 Bolt R Spatial Data Management Cambridge Massachusetts Massachu setts Institute of Technology Architecture Machine Group 1979 Sutherland I Sketchpad A Man Machine Graphical Communication System AFIPS Proceedings of the Fall Joint Computer Conference Vol 23 1963 pp 329 346 Sutherland W On Line Graphical Specifications of Computer Proced ures Cambridge Massachusetts Massachusetts Institute of Technology 1966 Christensen C An Example of the Manipulation of Directed Graphs in the AMBIT G Programming Language In M Klerer and J Reinfelds eds Interactive Systems for Experimental and Applied Mathematics New York Academic Press 1968 Kay A C The Reactive Engine Salt Lake City University of Utah 1969 Kay A C and the Learning Research Group Personal Dynamic Me dia Xerox Palo Alto Research Center Technical Report SSL 76 1 1976 A condensed version is in JEEE Computer March 1977 pp 31 41 Newman W M Officetalk Zero A User s Manual Xerox Palo Alto Research Center Internal Report 1977 Dahl O J and K Nygaard SIMULA An Algol Based Simulation Lan guage Communications of the ACM 9 1966 pp 671 678 Lampson B Bravo Manual In Alto User s Handbook Xerox Palo Alto Resear
34. s network resources A network based server architecture is economical since many machines can share the resources And it frees work stations for other tasks since most server actions happen in the background For example while a print server is printing your document you can edit another document or read your mail PHYSICAL OFFICE METAPHOR We will briefly describe one of the most important principles that influenced the form of the Star user interface The reader is referred to Smith et al for a detailed discussion of all the principles behind the Star design The principle is to apply users existing knowledge to the new situation of the com puter We decided to create electronic counterparts to the objects in an office paper folders file cabinets mail boxes calculators and so on an electronic metaphor for the phys ical office We hoped that this would make the electronic world seem more familiar and require less training Our ini tial experiences with users have confirmed this We further decided to make the electronic analogues be concrete objects From the collection of the Computer History Museum www computerhistory org The Star User Interface An Overview 519 Star documents are represented not as file names on a disk but as pictures on the display screen They may be selected by pointing to them with the mouse and clicking one of the mouse buttons Once selected documents may be moved copied or del
35. s visual communication to the ultimate extent we do claim that Star s use of imagery is a significant improvement over traditional human machine interfaces At the highest level the Star world is divided into two classes of icons 1 data and 2 function icons Data Icons Data icons Figure 4 represent objects on which actions are performed All data icons can be moved copied deleted filed mailed printed opened closed and have a variety of other operations performed on them The three types of data icons are document folder and record file From the collection of the Computer History Museum www computerhistory org 520 National Computer Conference 1982 Figure 4 The data icons document folder and record file Document A document is the fundamental object in Star It corre sponds to the standard notion of what a document should be It most often contains text but it may also include illustra tions mathematical formulas tables fields footnotes and formatting information Like all data icons documents can be shown on the screen rendered on paper sent to other people stored on a file server or floppy disk etc When opened documents are always rendered on the display screen exactly as they print on paper informally called what you see is what you get including displaying the correct type fonts multiple columns headings and footings illustration placement etc Documents can reside in th
36. ting properties e g fonts margins and then use those documents as form pad sources for new documents You select one push COPY and presto you have a new document The form pad documents need not be blank they can contain text and graphics along with fields for variable text such as for business forms You place new network resource icons e g printers file drawers on your Desktop by copying them out of the Directory The icons are registered in the Directory by a system administrator working at a server You simply copy them out no other initialization is required You create graphics by copying existing graphic images and modifying them Star supplies an initial set of such images called transfer symbols Transfer symbols are based on the idea of dry transfer rub off symbols used by many secretaries and graphic artists Unlike the physical transfer symbols however the computer versions can be modified they can be moved their sizes and proportions can be changed and their appearance properties can be altered Thus a single Star transfer symbol can produce a wide range of images We will eventually supply a set of documents transfer sheets containing nothing but spe cial images tailored to one application or another peo ple buildings vehicles machinery Having these as sources for graphics copying helps to alleviate the white canvas feeling In asense you can even type characters by copying them fro
37. tored for each user to increase as Star adds new functionality User icons may be placed in address fields for electronic mail User icons are Star s solution to the naming problem There is a crisis in computer naming of people particularly in elec tronic mail addressing The convention in most systems is to Figure 10 A user icon From the collection of the Computer History Museum www computerhistory org 522 National Computer Conference 1982 use last names for user identification Anyone named Smith as is one of the authors knows that this doesn t work When he first became a user on such a system Smith had long ago been taken In fact D Smith and even D C Smith had been taken He finally settled on DaveSmith all one word with which he has been stuck to this day Needless to say that is not how he identifies himself to people In the future peo ple will not tolerate this kind of antihumanism from comput ers Star already does better it follows society s conventions User icons provide unambiguous unique references to individ ual people using their normal names The information about users and indeed about all network resources is physically stored in the Clearinghouse a distributed database of names In addition to a person s name in the ordinary sense this information includes the name of the organization e g Xe rox General Motors and the name of the user s division within th
38. w to use the system Nearly all of its teaching and reference material is on line stored on a file server The Help facilities automatically retrieve the relevant material as you request it The HELP key on the keyboard is the primary entrance into this online information You can push it at any time and a window will appear on the screen displaying the Help table of contents Figure 20 Three mechanisms make finding infor mation easier context dependent invocation help references and a keyword search command Together they make the online documentation more powerful and useful than printed documentation Context dependent invocation The command menu in every window and property option sheet contains a command Invoking it takes you to a part of the Help documentation describing the window its commands and its functions The command also appears in the message area at the top of the screen invoking that one takes you to a description of the message if any cur rently in the message area That provides more detailed explanations of system messages Help references These are like menu commands whose effect is to take you to a different part of the Help mate rial You invoke one by pointing to it with the mouse just as you invoke a menu command The writers of the ma terial use the references to organize it into a network of interconnections in a way similar to that suggested by Vannevar Bush an
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