The document discusses different types of dialog design for user interfaces. It covers command languages, WIMP interfaces, direct manipulation, and speech/natural language interfaces. For each type, it describes key attributes and advantages and disadvantages. It provides examples and discusses design considerations for creating consistent and intuitive user interactions.

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SCHOOL OF INTERACTIVE ARTS + TECHNOLOGY [SIAT] | WWW.SIAT.SFU.CA
Dialog Design
Categories of Dialogs

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Agenda
 Dialog design
– Command Language
– WIMP - Window, Icon, Menu, Pointer
– Direct manipulation
– Speech/Natural language
– Gesture, pen, multi-touch, VR…

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Dialog Design
 How does a user interact with the
interface?

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Command Languages
 Earliest UI interaction paradigms
 Examples
– MS-DOS shell
– UNIX shell

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CL Attributes
 Work primarily by recall, not recognition
 Heavy memory load
 Little or nothing is visible
so…
 Poor choice for novices
but...

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CL Attributes
 Specify commands to operate on current
data collection
 User only controls initiation
 Single thread of control
 Some other display area needed

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CL Advantages
 Advantages for experts
– Speed, conciseness
• % ls <ret>
– Can express actions beyond a limited set
• Flags, pipes
– Repetition, extensibility
• Scripts, macros
– Easier implementation, less overhead
– Power
• eg. Wild cards

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CL Dangers
 With added power, comes added
responsibility and danger
– UNIX
% rm -r *
• Deletes every file that you have, and you can’t get
them back

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CL Reflection
 Command languages are often maligned
(for good reason)
 But increased functionality can win out
over bad UI (e.g., LINUX)
– Try to get both
– Avoid excess functionality (comes at cost)

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CL Design Goals
 Consistency
– Syntax, order
 Good naming and abbreviations
 Doing your homework in design can help
alleviate some of the negatives

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Consistency
 Provide a consistent syntax
– In general: Have options and arguments
expressed the same way everywhere
– UNIX fails here because commands were
developed by lots of different people at
different organizations
• No guidelines provided

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Dialog Order
 English: SVO subject verb object
 CL: S assumed (you)
Is VO or OV better? % rm file
% file rm
 V dO iO vs. V iO dO
% print file thePrinter
% lpr -PthePrinter file

13. Dialog Order
 Technical issues dictate the choice:
 V iO dO
% lpr -PthePrinter file
 The command must parse the arguments
– So the command comes first
 Flags control how to act on the file
– Want to parse all flags before checking files
– e.g. -o outputFile
Feb 10, 2011 IAT 334 13

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Syntax
 Pick a consistent syntax strategy
– Simple command list
• eg., vi minimize keystrokes
– Commands plus arguments
• realistic, can provide keyword parameters
• % cp from=foo to=bar
– Commands plus options plus arguments
• what you usually see

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Terminology
 Keep terminology consistent
– Same concept expressed with same options
– Useful to provide symmetric (congruent)
pairings
• forward/backward
• next/prev
• control/meta

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Example
 vi text editor
w - forward word
b - backward word
 Wouldn’t ‘f’ be better for forward?
‘f’ already used
 How about ‘fw’ and ‘bw’?
Extra keystrokes

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Ordering
 Keep ordering consistent
– VO seems to be the most natural
– Typically need to pick where options go
 Example
– % ln -s file1 file2 (I can never remember)
– Think of % cp file1 file2

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Names and Abbreviations
 Specificity versus Generality
– General words
• More familiar, easier to accept
– Specific (typically better)
• More descriptive, meaningful, distinctive
– (Nonsense does surprisingly well in small set)

19. Abbreviations
Feb 10, 2011 IAT 334 19

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Abbreviations
 Abbrevs. allow for faster actions
– Expert performance begins to be dominated
by motor times such as # of keystrokes
– Not good idea for novices
– (Allow but don’t require)
• IBM CMS and DEC VMS had shortened commands-
first unique characters were enough
• filelist -- f, fi, fil, file, filel, fileli, filelis, filelist

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Picking Good Abbrevs.
 Strategies
– Simple truncation (works best, but conflicts)
– Vowel drop plus truncation (avoid conflicts)
– First and last letters
– First letters of words in a phrase
– Standard abbrev from other contexts
• qty, rm, bldg
– Phonics
• xqt

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Abbrv Gdlns
 Use single primary rule (with single fallback for
conflicts)
– Use fallback as little as possible
– Mark use of fallback in documentation
 Let user know primary and secondary rules
 Truncation is good but generates conflicts
 Fixed length is better than variable length
 Don’t use abbrevs in system output

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Agenda
 Dialog design
– Command Language
– WIMP - Window, Icon, Menu, Pointer
– Direct manipulation
– Speech/Natural language
– Gesture, pen, multi-touch, VR…

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WIMP
 Focus: Menus, Buttons, Forms
 Predominant interface paradigm now
(with some direct manipulation added)
 Advantages:
– ?

25. Recognition
 Recognition is easier than recall!
– Recall has one cue
– Recognition has the recall cue + the presence
of the prompting word/icon
Feb 10, 2011 IAT 334 25

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Menus
 Key advantages:
– 1 keystroke or mouse operation vs. many
– No memorization of commands
– Limited input set

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Menus
 Many different types
– pop-up
– pull-down
– radio buttons
– pie buttons
– hierarchies

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Menu Items
 Organization strategies
– Create groups of logically similar items
– Cover all possibilities
– Ensure that items are non-overlapping
– Keep wording concise, understandable

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Bad Example
 Travel web page links:
– Flight page
– 3 Best Itineraries
– Flights & Prices
– Timetables
– Fares
 Which do you choose for reservations?

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Presentation Sequence
 Use natural if available
– Time
• e.g. Breakfast, Lunch, Dinner
– Numeric ordering
• e.g. Point sizes for font
– Size
• Canada-> BC -> Surrey

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Presentation Sequence
 Choices
– Alphabetical
– Group related items
– Frequently used first
– Most important first
– Conventional order (MTWRF)
 Don’t change the order on the fly!

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Presentation Sequence
 User studies
– Novices: alpha > functional > random
– Experts: categorization
 How would you do it in general?

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Presentation Sequence
 One possible methodology (first->last)
– Natural order (if it exists)
– Frequency of use
– Order of use
– Categorical
– Alphabetical
 Don’t change dynamically!

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Agenda
 Dialog design
– Command Language
– WIMP - Window, Icon, Menu, Pointer
– Direct manipulation
– Speech/Natural language
– Gesture, pen, multi-touch, VR…

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Direct Manipulation
 Continuous visibility of the objects and actions
of interest
 Rapid, incremental actions
 Reversibility of all actions to encourage
experimentation
 Syntactic correctness of all actions—every action
is syntactically legal
 Replacement of command language syntax by
direct manipulation of object of interest

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Direct Manipulation
 Examples
– WYSIWYG editors and word processors
– VISICALC - 1st electronic spreadsheet
– CAD
– Desktop metaphor
– Video games

37. DM Syntax
 Typical DM syntax is postfix
 DirectObjects first, Verb second
– In this case, the command completes the
utterance
 Enables separate selection syntax
 Indirect objects typically specified before
direct objects
– e.g. brush size before painting in Photoshop
Feb 10, 2011 IAT 334 37

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DM Essence
 Representation of reality that can be
manipulated
 The user is able to apply intellect directly to
the task
 Don’t have to name things, just touch them
 The tool itself seems to disappear

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DM Advantages
 Easier to learn & remember
 Direct WYSIWYG
 Flexible, easily reversible actions helps
reduce anxiety in users
 Provides context & instant visual feedback
 Exploits human use of visual spatial cues
 Limits types of errors

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DM Problems
 Takes of screen space
 Need to learn meaning of components of
visual representation
 Visual representation must be learned
 Mouse ops may be slower than typing
 Not self-explanatory (no prompts)

41. Direct Manipulation is
Locality
 DM Relies on a primary geometric organization
 Items located nearby are frequently edited
together
– The words in a sentence
– A column of numbers in a spreadsheet
 Less related -> Less local -> Less DM!
Feb 10, 2011 IAT 334 41

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DM Problems
 Not good at
– Repetition
– History keeping (harder)
– Certain tasks (Change all italics to bold)
– Macros harder
– Abstract elements (variables)

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What is Directness?
 Related to three things:
– Physical Distance
– “Gulfs” between user’s goals & system image
– Engagement
Hutchins, Hollan, Norman ‘86

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Distance: Two “Gulfs”
 Gulf of execution
– Distance between user’s goals and means of achieving
them in system
• Does the system allow the user to do what the user wants to
do?
 Gulf of evaluation
– Amount of effort person must expend to interpret
system state and judge if intention was achieved
• Can user perceive if progressing favorably?
Goals System
Execution
Evaluation

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Directness and Distance
 Two types
– Semantic - Relation between what user wants
to express and what is available in interface
• Can I say what I want (concisely)?
– Articulatory - Relation between meanings of
expressions and their physical form(s)
• Is the way to perform an action expected and
clear (appropriate)?

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Engagement
 Feeling that you are directly manipulating
the objects of interest
 Promoted by
– Unobtrusive interface
– Minimizing gulfs of execution and evaluation
– Appropriately responsive system

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Agenda
 Dialog design
– Command Language
– WIMP - Window, Icon, Menu, Pointer
– Direct manipulation
– Speech/Natural language
– Gesture, pen, multi-touch, VR…

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Speech Input
 Speech synthesis
 Speaker recognition
 Speech recognition
 Natural language understanding

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English Speech
 Made up of 40 phonemes, 24 consonants
and 16 vowels

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Speech Synthesis
 Often hear robotic voice
 Store tones, then put them together
– The transition is the difficult thing to do

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Speaker Recognition
 Tell which person it is (voice print)
 Could be important for monitoring
meetings

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Speech Recognition
 Primarily identifying words
 Improving all the time
 Commercial systems:
– IBM/Nuance ViaVoice, Ford Sync ...

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Recognition Dimensions
 Speaker dependent/independent
– Parametric patterns are sensitive to speaker
– With training can get better
 Vocabulary
– Some are getting 50,000+ words
 Isolated word vs. continuous speech
– Continuous: where words stop & begin
– Typically a pattern match, no context used

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Recognition Systems
Typical system has 5 components:
– Speech capture device - Has analog -> digital
converter
– Digital Signal Processor - Gets word boundaries,
scales, filters, cuts out extra stuff
– Preprocessed signal storage - Processed speech
buffered for recognition algorithm
– Reference speech patterns - Stored templates or
generative speech models for comparisons
– Pattern matching algorithm - Goodness of fit from
templates/model to user’s speech

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Errors
 Systems make four types of errors:
– Substitution – one word for another
– Rejection - detected, but not recognized
– Insertion – word added
– Deletion – word not detected
 Which is more common, dangerous?

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Natural Language
Understanding
 Putting meaning to the words
 Input might be speech or could be typed
 Holy grail of Artificial Intelligence
problems

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NL Factors/Terms
 Syntactic
– Grammar or structure
 Prosodic
– Inflection, stress, pitch, timing
 Pragmatic
– Situated context of utterance, location, time
 Semantic
– Meaning of words

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SR/NLU Advantages
 Easy to learn and remember
 Powerful
 Fast, efficient (not always)
 Little screen real estate

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SR/NLU Disadvantages
 Doesn’t work well enough yet
 Assumes knowledge of problem domain
– Not prompted, like menus
 Requires typing skill (if keyboard)
 Enhancements are invisible
 Expensive to implement

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Good in Situations
 Hands busy
 Mobility required
 Eyes occupied
 Conditions preclude use of keyboard
 Visual impairment
 Physical limitation