`
`Exhibit 1015 — Part 2
`
`
`
`Designing the User Interface
`
`anticipated. An extensive set of test conditions might be included as part
`of the requirements document.
`
`Beyond performance of productive decision-making tasks and handling
`of failures, the role of the human operator will be to improve the design
`of the system.
`In complex systems, an opportunity always exists for
`improvement, so systems that lend themselves to refinement will evolve
`under the continual incremental redesign by the operator.
`
`2.10 PRACTITIONER’S SUMMARY
`
`Designing user interfaces is a complex and highly creative process that
`blends
`intuition, experience,‘ and careful consideration of numerous
`technical
`issues. Designers are urged to begin with a thorough task
`analysis and specification of the user communities. Explicit recording of
`task objects and actions based on a task analysis can lead to construction
`of useful metaphors or system images.
`Identification of computer objects
`and actions guides designers to simpler concepts that benefit novice and
`expert users. Next, designers create consistent and meaningful syntactic
`forms for input and display. Extensive testing and iterative refinement
`are necessary parts of every development project.
`
`from practical
`emerging
`are
`guidelines
`and
`principles
`Design
`experience and empirical studies. Organizations can benefit by reviewing
`available guidelines documents and then constructing a local version. A
`guidelines document records organizational policies, supports consistency,
`aids the application of dialog management
`tools, facilitates training of
`new designers, records results of practice and experimental testing, and
`stimulates discussion of user interface issues.
`\
`
`2.11 RESEARCHER’S AGENDA
`
`The central problem for psychologists, human factors professionals,
`and computer scientists is to develop adequate theories and models of
`
`
`
`Ch. 2 Theories, Principles, and Guidelines
`
`79
`
`human behavior with interactive systems. Traditional psychological
`theories must be extended and refined to accommodate the complex
`human learning,
`‘memory,
`and problem-solving required in
`these
`applications. Useful goals include descriptive taxonomies, explanatory
`theories, or predictive models.
`A first step might be to investigate thoroughly a limited task for a
`single ‘community and to develop a formal notation for describing task
`actions and objects. Then the mapping tocomputer actions and objects
`could be made precisely. Finally, thelinkage with syntax would follow.
`This would lead to predictions of learning times, performance speeds,
`error rates,
`subjective satisfaction, or human retention over time for
`competing designs.
`4
`Next,
`the range of tasks and user communities could be expanded to
`domains of interest such as word processing,
`information retrieval, or
`data entry. More limited and applied research problems are connected
`with each of the hundreds of design" principles ‘or guidelines that have
`been proposed.. Each validation of these principles and clarification of
`the breadth of applicability would be a small and useful contribution to
`the emerging mosaic of human performance with interactive systems.
`
`REFERENCES
`
`Guide for
`Bailey, Robert W., Human Performance Engineering."
`System Designers, Prentice-Hall, Inc., Englewood Cliffs, NJ, (1982).
`Barber, Raymond E., Response time, operator productivity and job
`satisfaction, Ph. D. dissertation, NYU Graduate School of Business
`Administration (1979).
`'
`’
`Brown, C. Marlin, Human-Computer Interface Design Guidelines, Ablex
`A Publishing Company, Norwood, NJ (1986).
`Card, Stuart, Moran, Thomas P., and Newell, Allen, The keystroke—level
`model for user performance with interactive systems, Communications
`of the ACM 23, '(1980), 396-410}
`T
`'
`'
`’
`Card, Stuart, Moran, Thomas P., and Newell, Allen, The Psychology of
`Human—Computer
`Interaction,
`Lawrence
`Erlbaum Associates,
`Hillsdale, NJ, _(19s3), 469 pages.
`
`
`
`BO
`
`Designlng the User Intedace
`
`Eason, K. D., Dialogue design implications of task allocation between
`man and computer, Ergonomics 23, 9, (1980), 881-891.
`Foley, James D. and Van Dam, Andries, Fundamentals of Interactive
`Computer Graphics, Addison-Wesley Publishing Co., Reading, MA,
`(1982), 664 pages.
`
`Gaines, Brian R., The technology of interaction— dialogue programming
`rules,
`International Journal of Man—Machine Studies 14,
`(1981),
`133-150.
`
`Gaines, Brian R. and Shaw, Mildred L. G., The Art of Computer
`Conversation,
`Prentice—Hall
`International, Englewood Cliffs, NJ,
`(1984), 214 pages.
`
`Hansen, Wilfred J ., User engineering principles for interactive systems,
`Proceedings of the Fall Joint Computer Conference, 39, AFIPS Press,
`Montvale, NJ, (1971), 523532.
`Kieras, David, and Polson, Peter G., An approach to the formal analysis
`of user complexity, International Journal of Man-Machine Studies 22,
`(1985), 365-394.
`and Seymour,
`John, Singer, Andrew,
`Ledgard, Henry, Whiteside,
`William, ‘The natural language of interactive systems, Communications
`of the ACM 23, 10, (October 1980), 556-563.
`Lockheed Missiles and Space ' Company, Human Factors Review of
`Electric Power Dispatch Control Centers: Volume 2: Detailed Survey
`Results, Prepared for Electric Power Research Institute, 3412 Hillvicw
`Avenue, Palo Alto, CA 94304, (1981).
`
`Norman, Donald A., Design rules based on analyses of human error,
`Communications of the ACM 26, 4, (April 1983), 254-258.
`-
`Norman, Donald A., Stages and levels in human-machine interaction,
`International Journal of Man-Machine Studies 21, (1984), 365-375.
`Robertson, P. J ., A guide to using color on alphanumeric displays, IBM,
`Technical Report G320—6296, IBM, White Plains, NY, (1980).
`Rubinstein, Richard, and Hersh, Harry, The Human Factor: Designing
`Computer Systems for People, Digital Press, Burlington, MA, (1984),
`249 pages.
`
`Shneiderman, Ben, Software Psychology: Human Factors in Computer
`and Information Systems, Little, Brown and Co., Boston, MA, (1980).
`
`
`
`Ch. 2 Theories. Principles, and GUldel|fl€S
`
`81
`
`issues of natural
`‘Ben, A note on the human factors
`Shneiderman,
`language interaction with database systems, Information Systems 6, 2,
`(1981), 125-129.
`
`Shneiderman, Ben, System message design: Guidelines and experimental
`results, In Directions in Human—Computer Interaction, A. Badre and
`_B.
`Shneiderrnan (Editors), Ablex Publishing Co., Norwood, NJ,
`(1982), 55-78.
`
`Shneiderman, Ben, Direct manipulation: A step beyond programming
`languages, IEEE Computer 16, 8, (August 1983), 57-69.
`Shneiderman, Ben, and Mayer, Richard, Syntactic/Semantic interactions
`in
`programmer
`behavior: A model
`and
`experimental
`results,
`International Journal of Computer and Information Sciences 8, 3,
`(1979), 219-239. Reprinted in Curtis, Bill, (Editor), Human Factors
`in Software Development,
`IEEE Computer Society EHO 185-9,
`(1981), 9-23.
`
`Smith, Sid L., and Mosier, Jane N., Design Guidelines for the User
`Interface for Computer-Based Information Systems, The MITRE
`Corporation, Bedford, MA 01730, Electronic Systems Division,
`(September 1984), 448 pages. Available from the National Technical
`Information Service, Springfield, VA.
`Soloway, Elliot, Ehrlich, Kate, Bonar, ‘Jeffrey, and Greenspan, Judith,
`What do novices know about programming?,
`In Directions
`in
`Human—Computer
`Interaction, A. Badre
`and B.
`Shneiderman,
`(Editors), Ablex Publishing Co., Norwood, NJ, (1982), 27-54.
`Teitelbaum, T., and Reps, T.,. The Cornell program synthesizer: A
`-syntax—directed prograrnniing environment, Cornrnunications of the
`ACM 24, 9, (September 1981), 563-573.
`
`
`
`PART II
`
`INTERACTION STYLES
`
`
`
`CHAPTER 3
`
`MENU SELECTION SYSTEMS
`
`A man is responsible for his choice
`and must accept the consequences,
`whatever they may be.
`
`W. H. Auden, A Certain World.
`
`
`
`Designing the User Interface
`
`3. 1
`
`INTRODUCTION
`
`Menu selection systems are attractive because they can eliminate
`training and memorization of complex command sequences. When the
`menu items are written using familiar terminology, users can select an
`item easily and indicate their choice with one or two keypresses or use of
`a pointing device. This simplified interaction style reduces the possibility
`of keying errors and structures
`the task to guide the novice and
`intermittent user. With careful design and high-speed interaction, menu
`selection can become appealing to expert frequent users, as well.
`
`the
`Menu selection is often contrasted with command language, but
`distinctions are sometimes blurred. Typically, menu selection requires a_
`single keystroke, whereas commands may be lengthy; but how would you
`classify a menu in which the user has to type a six- or eight-letter item?
`Typically, menu selection presents the choices on the display, whereas
`commands must be memorized, but how would you classify a menu that
`offered four numbered choices and accepted ten more generic choices that
`are not displayed? How would you classify a system that offers single
`letter prompts? What about graphical,
`two—dimensional menus in which
`selection is made by pointing or voice synthesis/recognition menu
`interaction?
`I
`
`it is more useful to maintain an
`Rather than debate over terminology,
`awareness of how much the system offers on the display at the moment
`the selection is made, the form and content of item selection, and what
`
`task domain knowledge is necessary for users to succeed. Menu selection
`is especially effective when users have little training, are intermittent in
`using the system, are unfamiliar with the terminology, and need help in
`structuring their decision—making process.
`
`However, if a designer uses menu selection, it does not guarantee that
`the system will be appealing and easy to use. Effective menu selection
`systems emerge only after careful consideration and testing of numerous
`design issues, such as semantic organization, menu system structure, the
`
`titling, prompting format, graphic
`number and sequence of menu items,
`layout and design, phrasing of menu items, display rates, response time,
`shortcuts
`through
`the menus
`for
`knowledgeable
`frequent
`users,
`availability of help, and the selection mechanism (keyboard, pointing
`devices, touchscreen, voice, etc.).
`
`
`
`Ch. 3 Menu Selection Systems
`
`87
`
`3.2 SEMANTIC ORGANIZATION
`
`a sensible,
`to create
`is
`for menu designers
`The primary goal
`organization
`semantic
`comprehensible, memorable,
`and
`convenient
`relevant to the user's tasks. Some lessons can be learned by organizing
`the semantic decomposition of a book into chapters, a program into
`modules,
`the animal kingdom into species, or a Sears catalog into
`sections. Hierarchical decompositions," natural and cnomprehenhsible to
`most people, are appealing because every" item belongs to a
`single
`category. Unfortunately, in some applications an item may be difficult to
`classify‘ as belonging to one category, and the temptation to duplicate
`entries or create a network increases.
`In spite of some limitations‘,
`the
`elegance of tree structures should be appreciated.
`'
`Restaurant menus separate appetizers, soups, main dishes, desserts, and
`drinks to help customers organize their selections. Menu items should fit
`logically
`into
`categories
`and
`have
`readily understood meanings.
`Restauranteurs who list ‘dishes with idiosyncratic names such _as “Veal
`Monique,” genetic terms such as “House dressing,” or unfamiliar jargon
`such as “Wor Shu Op” should expect waiters to spend ample time
`explaining the altematives or anticipate customers becoming anxious
`because of their insecurity in ordering.
`I
`Similarly, for computer menu selection systems, the categories should
`be comprehensible and distinctive so that
`the users are confident in
`making their selections. Users should have a clear idea of what will
`happen when they make a choice. Computer menu selection systems are
`more difficult to design than restaurant menus because computer" screens
`typically allow less information to'be displayed than printed menus.
`Screen space ‘is a scarce resource.
`In addition, the number of choices and
`the ciomplexity is “greater
`in many computer applications,
`and
`computer user may not have a helpful“ waiter
`to turn to for an
`explanation.
`
`The importance of meaningful organization of menu items was
`demonstrated in a study with 48 novice users (Liebelt et al., 1982).
`Simple menu trees with 3 levels and 16 target items were constructed in
`meaningfully organized and disorganized forms. Error rates were nearly
`halved and user think time (time from menu presentation to user’s
`selection of an item) was reduced. for the meaningfully organized form.
`
`
`
`86
`
`Designing the User Interface
`
`3.]
`
`INTRODUCTION
`
`Menu selection systems are attractive because they can eliminate
`training and memorization of complex command sequences. When the
`menu items are written using familiar terminology, users can select an
`item easily and indicate their choice with one or two keypresses or use of
`a pointing device. This simplified interaction style reduces the possibility
`of keying errors and structures
`the task to guide the novice and
`intermittent user. With careful design and high-speed interaction, menu
`selection can become appealing to expert frequent users, as well.
`
`Menu selection is often contrasted with command language, but the
`distinctions are sometimes blurred. Typically, menu selection requires a
`single keystroke, whereas commands may be lengthy; but how would you
`classify a menu in which the user has to type a six~ or eight—1etter item?
`Typically, menu selection presents the choices on the display, whereas
`commands must be memorized, but how would you classify a menu that
`offered four numbered choices and accepted ten more generic choices that
`are not displayed? How would you classify a system that offers single
`letter prompts? What about graphical,
`two—dimensional menus in which
`selection is made by pointing or voice synthesis/recognition menu
`interaction?
`'
`
`Rather than debate over terminology, it is more useful to maintain an
`awareness of how much the system offers on the display at the moment
`the selection is made, the form and content of item selection, and what
`task domain knowledge is necessary for users to succeed. Menu selection
`is especially effective when users have little training, are intermittent in
`using the system, are unfamiliar with the terminology, and need help in
`structuring their decision-making process.
`
`However, if a designer uses menu selection, it does not guarantee that
`the system will be appealing and easy to use. Effective menu selection
`systems emerge only after careful consideration and testing of numerous
`design issues, such as semantic organization, menu system structure,
`the
`number and sequence of menu items,
`titling, prompting format, graphic
`layout and design, phrasing of menu items, display rates, response time,
`shortcuts
`through
`the menus
`for
`knowledgeable
`frequent
`users,
`availability of help, and the selection mechanism (keyboard, pointing
`devices, touchscreen, voice, etc.).
`
`
`
`Ch. 3 Menu Selection Systems
`
`87
`
`3.2 SEMANTIC ORGANIZATION
`
`sensible,
`a
`to create
`is
`for menu designers
`The primary goal
`organization
`semantic
`comprehensible, memorable,
`and
`convenient
`relevant to the user’s tasks. Some lessons can be leamed by organizing
`the semantic decomposition of a book into chapters, a program into
`modules,
`the animal kingdom into species, or a Sears catalog into
`sections. Hierarchical decompositions, natural and comprehensible to
`most people, are appealing because every’ item belongs to a single
`category. Unfortunately, in some applications an item may be difficult to
`classify. as belonging to one category, and the temptation to duplicate
`entries or create a network increases.
`In spite of some limitations‘,
`the
`elegance of tree structures should be appreciated.
`Restaurant menus separate appetizers, soups, main dishes, desserts, and
`drinks to help customers organize their selections. Menu items should fit
`logically
`into
`categories
`and
`have
`readily
`understood meanings.
`Restauranteurs who list dishes with idiosyncratic names such as “Veal
`Monique,” generic terms suchas "‘House dressing,” or unfamiliar jargon
`such "as “Wor Shu Op” should expect waiters to. spend ample time
`explaining the altematiyes or anticipate customers becoming anxious
`because of their insecurity in ordering.
`A
`A
`'
`
`the categories should
`Similarly, for computer menu seiection systems,
`be cornprehehsible and distinctive so that
`the users are confident in
`making their selections. Users should have a clear’ idea of what will
`happen when they make a choice. Computer menu selection systems are
`more difficult to design than restaurant menus because computer" screens
`typically allow less information totbe displayed than printed menus.
`Screen space is a scarce resource.
`In addition, the number of choices and
`the complexity is “greater
`in many computer applications,
`and the
`computer user may not have a helpful waiter
`to turn to for an
`explanation.
`i
`I
`
`importance of meaningful organization of menu items was
`The
`demonstrated in a study with 48 novice users (Liebelt et al., 1982).
`Simple menu trees with 3 levels and 16 target items were constructed in
`meaningfully organized and disorganized forms. Error rates were nearly
`halved and user
`thinlg time (time from menu presentation to user’s
`selection of an item) was reduced‘ for the meaningfully organized fonn.
`
`
`
`88
`
`Designing the User Interface
`
`In a later menu search study, McDonald, Stone, and Liebelt (1983) found
`that semantically meaningful categories, such as food, animals, minerals,
`and cities,
`lead to shorter response times than do random or alphabetic
`organizations, This experiment
`tested 109 novice users who worked
`through 10 blocks of 26 trials. The authors conclude that “these results
`demonstrate the superiority of a categorical menu organization over a
`pure
`alphabetical
`organization,
`particularly when
`there
`is
`some
`uncertainty about the terms.” With larger menu structures the effect
`is
`evenimore dramatic, as has been demonstrated by studies with extensive
`videotex databases (Lee & Latremouille, 1980; McEwen, 1981).
`
`These results and the syntactic/semantic model suggest that the key to
`menu structure design is first to consider the semantic organization. The
`number of items on the screen becomes a secondary issue.
`
`Menu selection applications range from trivial choices between two
`items to complex videotex systems with 300,000 screens. The simplest
`applications "consist of a single menu, but even with this limitation there
`are many variations-(Figure 3.1). The second group of applications
`includes a- linear sequence of menu selections; the progression of menus
`is independent of the user’s choice. Strict tree structures make up the
`third group, which is the most common situation.
`.Acyclic (menus which
`are reachable by more ‘than one path) and cyclic (menus with meaningful
`paths that allow users to repeat menus) networks constitute thefourth
`group. These groupings describe the semantic organization;
`special
`traversal commands may enable users to jump around the branches of a
`tree,
`to go back to the previous menu, or to go to the-beginning of a
`linear sequence.
`
`3.2.] Single menus
`
`In some situations, a single menu is sufficient to accomplish a task.
`Single menus may have two or more items, may require two or more
`screens, or may allow multiple selections. Single menus may pop up on
`the current work area or may be permanently available (in a separate
`window or on a data tablet) while the main display is changed. Different
`guidelines apply for each situation.
`
`
`
`Ch. 3 Menu Selection Systems
`
`89
`
`El
`Single Menus
`
`@ E7
`Linear Sequence
`
`Acyclic Network
`
`Cyclic Network
`
`Figure 3.1: Menu systems can use simple single or linear sequences of menus.
`Tree—str11ct'ured menus are the most common structure. More elaborate acyclic or
`
`cyclic menu structures can become difficult for some users.
`
`Binary menus: The simplest case is a binary menu with yes/no or
`true/false choices, such as is found in many home computer games:
`
`DO YOU WANT INSTRUCTIONS (Y,N)‘?
`
`Even this simple example can be improved. A novice user might not
`understand the (Y,N) pr0mpt—really an abbreviated form of the menu
`of choices. Second,
`this common query leaves the user without a clear
`Sense of what is going to happen next. Typing Y might produce many
`
`
`
`90
`
`Designing the User interface
`
`pages of instructions and the user might not know how to stop a lengthy
`output. Typing N is also anxiety producing because the user has no idea
`of what the program will do. Even in writing simple menus, clear and
`specific choices should be offered that give the user the sense of control:
`
`Your choices are:
`
`1 — Get 12 lines of brief instructions.
`2 — Get 89_1ines of complete instructions.
`3 — Go on to playing the game.
`Type 1, 2, or 5 and press RETURN:
`
`It
`is no longer a binary menu.
`it
`Since this version has three items;
`offers more specific items so the user knows what to expect, but it still
`has the problem that users must take instructions now or never. Another
`strategy might be:
`
`At any time, you may type
`? — Get 12 lines of brief instructions.
`?? — Get 89 lines or complete instructions.
`Be sure to press RETURN after every command
`Ready for game playing commands:
`
`This example calls attention to the sometimes narrow distinction between
`commands "and menu selection;
`the menu choices have become more
`commarid—like' since the user must now recall the ? or ?? syntax.
`Menu items can be identified by single letter mnemonics, as in this
`photo library retrieval system:
`
`Photos are indexed by film type
`
`Blaok and white
`Color
`
`v c
`
`B
`
`Type the letter of your choice
`and press RETURN:
`'
`
`The rrmemonic letters in this menu are often preferred to the numbered
`choices
`(see Section 3.7).
`The mnemonic letter approach requires
`
`
`
`Ch. 3 Menu Selection Systems
`
`91
`
`the effort of
`additional caution in avoiding collision and increases
`translation to foreign langauges, but its clarity and memorability are an
`advantage in many applications.
`
`These simple examples demonstrate alternative ways to identify menu
`items and convey instructions to the user. No optimal format for menus
`has emerged, but consistency across menus in a system is extremely
`important.
`
`Multiple item menus: Single menus may have more than two items.
`Examples include online quizzes with a touchscreen:
`
`Who invented the telephone?
`Thomas Edison
`
`Alexander Graham Bell
`
`Lee De Forest
`
`George Westinghouse
`Touch your answer.
`
`or the list of options in a document processing system:
`
`EXAMINE, PRINT, DROP, OR HOLD?
`
`The quiz example has distinct, comprehensible items, but the document
`processing example shows an implied menu selection that could be
`confusing to novice users. There are no explicit instructions and it is not
`apparent that single letter abbreviations are acceptable. Knowledgeable
`and frequent users may prefer this short form of a menu selection, usually
`called a prompt, for its speed and simplicity.
`
`Extended menus: Sometimes the list of menu items may require more
`than one screen but allow only one meaningful item to be chosen. One
`resolution is to create a tree structured menu, but sometimes the desire to
`
`keep the system to one conceptual menu is very appealing. The first
`portion of the menu is displayed with an additional menu item that leads
`to the next screen in the extended menu sequence. A typical application
`is in word processing systems, where common choices are displayed first,
`but infrequent or advanced features are kept on the second screen:
`
`
`
`92
`
`Designing the User Interface
`
`SUPERDUPERWRITER MAIN MENU
`PAGE l
`
`Edit a document
`
`Copy a document
`Create a document
`Erase a document
`Print a document
`View the index of documents
`
`Type the number of your choice
`or M for more choices.
`
`Then Press RETURN
`
`SUPERDUPERWRITER MAIN MENU
`PAGE 2
`
`7 Alter line width
`
`8 Change character set
`9 Attempt recovery of damaged file
`10 Reconstruct erased file
`11 Set cursor blink rate
`
`12 Set beep volume
`13 Run diagnostics
`
`Type the number of your choice
`
`or P to go back to Page 1.
`Then Press RETURN
`
`Sometimes the extended screen menu will continue for many screens of
`command items or data items. More elaborate scrolling capabilities may
`be needed.
`
`Pop—up menus: Pop-up or pull down menus appear on the screen in
`response to a click with a pointing device such as a mouse. The Xerox
`Star, Apple Lisa,
`and Apple Macintosh (Figure 3.2) made these
`possibilities widely available. Selection can be made by moving the
`
`
`
`Ch. 3 Menu Selection Systems
`
`93
`
`.
`
`.
`.1._.l4l..l.i.l°.i.1.l.
`E] Clfihnesflinch
`
`Bald
`#6,”
`underline
`fllmtlllflme
`IIIEJEIIDED
`Superscript
`DEFARTt1ENT or com ‘“'’“'''|“
`EEIURSE AND msreuci ‘Q mm
`.£.l.l‘.J.l.l‘l‘>s.l..Al.J.EJ_ flmpmflmfl
`5llm?‘3.’1r‘tE‘i| % IE ~/112 Pmumfl
`ll-‘al-Epflllllilil
`MB IPGJIJHJQ
`
`.
`
`-students with
`Tlwis evaluation form has been? 2'? Emma
`helpful information for selecting courses and teachers. ".15 also intended
`to assist professors in evaluating their p>_=.rforrnence as teachers.
`
`The form, divided into two parts, consists of Part A which
`
`Figure 3.2: The pull—down menu on the Apple Macintosh MacWrite program
`enables users to select
`font variations and size.
`(Photo courtesy of Apple
`Computer, Inc.)
`
`pointing device over the menu items that respond by highlighting (reverse
`video, a box surrounding the item, or color have been used).
`
`The contents of the pop—up menu may depend on where the cursor is
`when the pointing device is clicked. Since the pop—up menu covers a
`portion of the screen, there is strong motivation to keeping the menu text
`small. Hierarchical sequences of pop—up menus are also used.
`
`Permanent menus: Single menus can be used for permanently available
`commands that can be applied to a displayed object. For example,
`the
`Bank Street Writer, a word processor designed for children, always
`shows a fragment of the text and this menu
`
`FIND
`MOVE
`ERASE
`UNERASE MOVEBACK REPLACE
`
`TRANSFER
`MENU
`
`Moving the left and right arrow keys causes items to be sequentially
`highlighted in reverse video. When the desired command is highlighted,
`pressing the RETURN key initiates the action.
`
`
`
`Designing the User Interface
`
`include Apple Macpaint,
`Other applications of permanent menus
`computer-assisted design systems, or other graphics systems that display
`an elaborate menu of commands
`to the side of
`the object being
`manipulated. Price (1982) describes a CAD system with 120 choices in
`an on-screen menu. Lightpen touches or other cursor action devices
`allow the user to make selections without using the keyboard.
`
`Multiple selection menus: A further variation on single menus is the
`capacity to make multiple selections from the choices offered. For
`example, a political interest survey might allow multiple choice on one
`screen (Figure 3.3). A multiple selection menu with mouse clicks for
`selection is a convenient strategy for handling multiple binary choices,
`since the user gets to scan the full list of items while deciding.
`
`Summary: Even the case of single menus provides a rich domain for
`designers and human factors researchers. Questions of wording, screen
`layout, and selection mechanism all emerge even in the simple case of
`choosing from one set of items. Still more challenging questions emerge
`from designing sequences and trees of menus.
`
`POLITICHL
`
`ISSUES
`
`Hid +0 Elderlg
`
`I Cir‘-ime |:DFl'l'l"L'Jl
`
`DONE‘
`
`Figure 3.3: This multiple selection touchscreen menu enables users to make up to
`three selections of political issues.
`
`
`
`Ch. 3 Menu Selection Systems
`
`95
`
`the document printed at
`Do you want
`1 — your terminal
`
`2 — the computer center line printer
`‘
`3 — the computer center laser printer
`Type the number of your choice and press RETURN:
`
`Do you want
`
`1 — single spacing
`2 — one and a half spacing
`
`3 — double spacing
`
`4
`4 — triple spacing
`Type the number of your choice and press RETURN:
`
`Do you want
`
`1 — no page numbering
`right justified
`2 - page numbering on the top,
`3 — page numbering at the bottpm, centered_
`Type the number of your choice and press RETURN:
`
`three print
`Figure 3.4: A linear sequence of menus allows the userto select
`parameters for a document: printing device, line spacing, and page numbering.
`
`3.2.2 Linear sequence of menus
`
`Often a series of interdependent menus can be used to guide the user
`through a series of choices in which the user sees the same sequence of
`menus no matterpwhat choices are made. A document printing package
`might have a linear sequence of menus to choose print parameters such as
`device, line spacing; and_ page numbering (Figure 3.4). Another familiar
`example is an online examination that has a sequence of multiple choice
`test items, each made up as a menu.
`‘
`is possible to
`it
`With high resolution screens and pointing devices,
`include several menus on a single screen,
`thereby simplifying the user
`interface and speeding usage (Figure 3.5).
`
`
`
`Designing the User Interface
`
`CHARACTERPROPERTIES
`T
`l 1?‘ H:Done “Cancel Nfpplyj
`
`Figure 3.5: This property sheet allows users to select the character properties on
`the Xerox Star. The user moves the cursor with a mouse and then presses the
`mouse button to select the item.
`(Used with permission of Xerox Corporation;
`Xerox, 8010 Information System, Standard Workstation Software are trademarks
`of XEROX CORPORATION.)
`
`Movement through the menus: Linear sequences guide the user through
`a complex decision-making process by presenting one decision at a time.
`The document printing example could be improved by offering the user
`several menus on the screen at once.
`If the menus do not fit on one
`
`then there should be a mechanism for going back to previous
`screen,
`to
`review or
`change
`choices made
`earlier.
`A second
`screens
`improvement
`is
`to display previous choices,
`so users can see what
`decisions have been made. A third improvement might be to let the users
`know how many and which menus are yet to be seen.
`
`Summary: Linear sequences of menus are a simple and effective means
`for guiding the user through a decision-making process. The user should
`be given a clear sense of progress or position within the sequence and the
`means for going backwards to earlier choices (and possibly to terminating
`or restarting the sequence).
`
`is often
`sequence
`linear
`a
`in
`Choosing the order of menus
`straightforward, but care must be taken to match user expectations. One
`strategy is to place the easy decisions first
`to relieve users of some
`concerns, enabling them to concentrate on more difficult choices.
`
`
`
`Ch. 3 Menu Selection Systems
`
`3.2.3 Tree structured menus
`
`When a collection of items grows and becomes difficult to maintain
`under
`intellectual control, people form categories of similar
`items,
`creating a tree structure (Clauer, 1972; Brown, 1982). Some collections
`can be easily partitioned into mutually exclusive groups with distinctive
`identifiers. Familiar examples include:
`
`male, female
`animal, vegetable, mineral
`spring, summer, autumn, winter
`Sunday, Monday, Tuesday, Wednesday, Thursday,
`
`Friday, Saturday
`less than 10, between 10 and 25, greater than 25
`percussion, string, woodwind, brass
`
`or
`confusion
`to
`lead
`occasionally
`groupings may
`these
`Even
`disagreement. Classification and indexing are complex tasks, and in
`many situations there is no perfect solution acceptable to everyone. The
`initial design can be improved as a function of feedback from users.
`Over time, as the structure is improved and as users gain familiarity with
`it, success rates will improve.
`In spite of their problems, tree structured menu systems have the power
`to make large collections of data available to novice or intermittent users.
`If each menu has 8 items, then a menu tree with 4 levels‘ has the capacity
`to lead an untrained user to the right frame out of a collection of 4,096
`frames .
`
`If the groupings at each level are natural and comprehensible to the
`user, and if the user knows what he or she is looking for, then the menu
`traversal can be accomplished in a few seconds—more quickly than
`flipping through a book. On the other hand,
`if the groupings are
`unfamiliar and the user has only a vague notionof what he or she is
`looking for, getting lost
`in the tree menus
`for hours
`is possible
`(Robertson et a1., 1981).
`
`Instead
`Terminology from the user’s task domain can orient the user.
`of using a title such as MAIN MENU OPTIONS that
`is vague and
`
`
`
`98
`
`Designing the User Interface
`
`emphasizes the computer domain, use terms such as FRIENDLIBANK
`SERVICES or simply GAMES.
`,
`Depth versus breadth: The depth (number of levels) of a menu tree
`depends,
`in part, on the breadth (number of items _per level).
`If more
`items are put into the main menu, then the tree spreads out and has fewer
`levels.
`This
`is advantageous; but not
`if M clarity is
`substantially
`compromised or if a slow display rate consumes the user’s patience.
`Several authors have urged