9. Interaction Devices

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9. Interaction Devices

• Keyboards and Keypads
• Keyboard layouts
• QWERTY layout (Christopher Latham Sholes), Dvorak
  layout, ABCDE style
• number pads telephone layout and calculator
  layout
• wrist and hand placement awkward
• Keys
• ½-inch-square keys (12 mm square), concave
  surface with a matte finish
• 40- to 125-gram force and a displacement of 3 to
  5 mm, tactile and audible feedback
• larger for reliable access, locking by embedded
  light, labels, home keys (F and J)
• Function keys, Cursor movement keys -- inverted T
  arrangement, auto-repeat feature
• Keyboards and keypads for small devices
• reduced, wireless, foldable, virtual keyboards,
  softkeys
• tap on virtual keyboards, handwrite on a touch
  sensitive surface (Graffiti)
• Pointing Devices
• Pointing tasks
• 6 types of interaction tasks -- Select, Position,
  Orient, Path, Quantify, Text
• direct control (light pen, touchscreen, stylus)
  vs. indirect control (mouse, trackball, joystick,
  etc)
• Direct-control pointing devices
• lightpen incorporate a button arm fatigue,
  hands obscuring part of the screen, users
  removing hands from the keyboard, picking up the
  lightpen

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• touchscreen (fatigue, obscuring the screen, hand
  off keyboard, imprecise pointing, smudging of the
  display) land-on strategy, lift-off strategy
• pointing on the LCD surface handwriting
  recognition, stylus
• Indirect-control pointing devices
• more cognitive processing and hand-eye
  coordination
• mouse, trackball, joystick, trackpoint, touchpad,
  graphics tablet
• Comparison of pointing devices
• direct pointing devices fastest but the least
  accurate devices
• mouse for speed and accuracy, mouse was found to
  be faster than the trackpoint
• users tasks matter browsing, precision
  pointing
• Fitts Law
• the pointing time is a function of the distance
  and the width
• well established for adults users
• Novel devices
• foot controls, eye-tracking (Midas touch
  problem), DataGlove
• ubiquitous computing and tangible user interfaces
• handheld devices
• Speech and Auditory Interfaces
• Discrete-word recognition
• recognize individual words spoken by a specific
  person 90-98 reliability for 100- to
  10,000-word or larger vocabularies

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• speaker dependent training, speaker independent
  system
• hands are busy mobility required eyes
  occupiedharsh or cramped conditions
• recognition rate background sounds change, user
  is ill or under stress, similar vocabulary
• more demanding of working memory than the
  hand/eye coordination
• Continuous-speech recognition
• difficulty in recognizing the boundaries between
  spoken words
• Voice information systems
• Speech generation
• synthesis in some cases, removal of speech
  generation
• Non-speech auditory interfaces
• audio tones confirmation for most users, vital
  for the impaired after 2 hrs, distraction
• auditory icons (familiar sounds), earcons
• Displays Small and Large
• Display technology
• CRT, LCDs, Plasma panel, LEDs, Electronic ink,
  Braille displays
• Large displays
• information wall displays (situation awareness),
  interactive wall displays, multiple desktop
  displays
• Heads-up and helmet-mounted displays
• Mobile device displays

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• Animation, image, and video
• digital photography, optical character
  recognition, videodisks, CD-ROMs, digital
  versatile disks (DVDs), motion picture experts
  group (MPEG), MP3
• Printers
• thermal printers, dot-matrix printers, inkjet
  printers, impact-line printers, laser printers
• plotters, photographic printers
• braille embossers
• three-dimensional printers

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10. Collaboration

• Goals of Collaboration
• collaboration by the goals and tasks of the
  participants
• Focused partnership collaboration between two
  or three people email, chat, instant messages,
  voice mail, telephone, video conferencing, SMS,
  photo exchanging
• Lecture or demo one person sharing info with
  many users at remote sites the start time and
  duration is the same for all no history keeping
• Conferences groups communicate at the same time
  or spread out over time, but with participants
  distributed in space a record of previous
  conversation, blogs, wikis
• Structured work processes let people with
  distinct organization roles collaborate on some
  task
• Electronic Commerce negotiations can be
  distributed in time and space
• Meeting and decision support face-to-face
  meeting with simultaneous contributions
  anonymity
• Electronic commerce customers browsing and
  comparing prices, accurate recording and rapid
  dissemination of results
• Teledemocracy produce consensus through online
  conferences, debates, and votes
• online communities communities of interest
  (Cols), communities of practice (CoPs), networked
  communities
• collaboratories
• telepresence immersive SD VR
• time-space matrix (Ellis et al., 1991)

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• Asynchronous Distributed Interfaces Different
  Place, Different Time
• Electronic Mail
• Newsgroups, listservers, discussion boards,
  conferences, blogs, and wikis
• newsgroups organized into hierarchies to help
  users to find topics of interest
• listserv individuals must subscribe to receive
  email notices online conference
• discussion board evolved from bulletin board
• web-logs (blogs)
• wikis collaborative web pages that are open for
  anyone to add or revise content
• online magazines, newsletters, journals
• Online and networked communities
• topically focused and geographically dispersed
• shared goal, identity, or common interest and
  participate on a continuing basis
• Synchronous Distributed Interfaces Different
  Place, Same Time
• Chat, instant messaging, and texting
• Audio and video conferencing
• video conferencing, DTVC (desktop
  videoconferencing) slow response time,
  background noise, inappropriate lighting, eye
  contact difficulty, small image size, privacy
  invasion, jerky motion

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• Face to Face Interfaces Same Place, Same Time
• Electronic meeting rooms, control rooms, and
  public spaces
• brainstorming, voting, and ranking
• parallel communication, anonymity, group memory,
  process structure, task support and structure
• Electronic classrooms

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11. Quality of Service

• Introduction
• quality of service time is precious harmful
  mistakes should be avoided reduce user
  frustration
• focus on the decisions to be made by network
  designers and operators
• Models of Response-Time Impacts
• response time the number of seconds it takes
  from the moment users initiate an activity until
  the computer begins to present results o the
  display or printer
• lengthy (gt 15 sec) response time ?
  productivity,?error rate, ?satisfaction
• more rapid (lt 1 sec) ? productivity, ? error
  rate for complex tasks
• display rate the speed, in characters per
  second (cps), at which characters appear for the
  user to read graphics in bytes per seconds
• cognitive model of human performance in response
  time useful in making predictions, designing
  interfaces, formulating management policies
• Robert B. Millers review (1968) 17 situations
  where response time differ but the principle of
  closure, short-term memory limitations, and
  chunking still apply
• Limitations of short-term and working memory
• George Miller (1956) the magical number seven
  plus or minus two ? seven chunks of info. in
  working memory for 15 to 30 seconds familiarity

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• STM processes perceptual input, whereas WM is
  used to generate and implement solutions
• Highly volatile, disruptions cause loss in info,
  delays can require that the memory be refreshed
• Sources of errors
• interference, delay preferred response time
• long response time leads to wasted effort and
  more errors because a solution plan is reviewed
  repeatedly
• short response times may generate a faster pace
  in which solution plans are prepared hastily and
  incompletely
• Conditions for optimum problem solving
• Wickelgren (1977) -- speed-accuracy tradeoffs
• feedback -- graphical dynamic progress indicators
• Expectations and Attitudes
• acceptable response time 2-second limit
• previous experience
• individuals tolerance for delays
• task complexity and the users familiarity with
  the task
• longer response time web-page content less
  interesting, lower in quality, negative user
  perception of the companies
• three conjectures

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• User Productivity
• The nature of the task influence on changes in
  response time alter user productivity
• With shorter system response times works more
  quickly but decisions less than optimal
• with a data-entry task, three strategies on the
  response time
• RTlt1 sec, worked automatically without checking
  for the next data value
• RTgt2, monitored the display carefully
• In between, users paced themselves
• users will adapt their work style to the
  response time
• Variability in Response Time
• Extreme variation in response time is unsettling
  and should be prevented or acknowledged
• The effect of modest variations in response time
• people detect 8-percent changes in a 2 or 4 sec
  response time ? a fixed short response time not
  for all actions but for classes of actions
• modest variations in response time do not
  severely affect performance (adapting) but
  extreme variation should be prevented or
  acknowledged by the interface
• With shorter RT, hasty decision with longer RT,
  frustration of waiting burdened STM
• physiological effect of response time ? higher
  error rates, higher systolic blood pressure, more
  pronounced pain symptoms with shorter response
  time
• Frustrating Experiences
• major sources of problems web browsing, e-mail,
  word processing
• interface redesign, software quality improvement,
  network reliability increases
• increased learning, careful use of services,
  self-control of their attitudes

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12. Balancing Function and Fashion

• Error Messages
• lack of knowledge, incorrect understanding,
  inadvertent slips
• Specificity
• Constructive guidance and positive tone
• what uses need to do to set things right
• User-centered phrasing
• Appropriate physical format
• mixed uppercase and lowercase messages
• optimal placement proximity, consistent place
  (the bottom line), dialog box not obscuring the
  problem
• alarm users control
• Development of effective messages
• upgrade performance and greater job satisfaction
• Nonanthropomorphic Design
• may give users an erroneous model of how
  computers work and the machines capacities
• to clarify the differences between people and
  computers
• an anthropomorphic interface can be distracting
  or produce anxiety for others
• Walker, Sproull, Subramani (1994)
  incautiously adding human characteristics like
  face, voice, and facial expressions could make
  the experience for users worse than better
• external locus of control by animated characters
  increase anxiety and reduce performance
• use of first-person pronouns deceive, mislead,
  confuse users

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• Display Design
• dense or cluttered displays can provoke anger,
  and inconsistent formats can inhibit performance
• Field layout
• Empirical results
• data label, clustering related info, appropriate
  indentation and underlining ? improve performance
• consistent location, structure, terminology,
  sequence of displays
• Display-complexity metrics
• four task-independent metrics for alphanumeric
  displays (Tullis, 1997)
• overall density, local density, grouping, layout
  complexity
• displays that optimize search times do not
  necessarily optimize subjective ratings
• fast performance ? grouping of items high
  subjective ratings ? low local density and low
  layout complexity
• effective display design 6 to 15 groups neatly
  laid out, surrounded by blanks, similarly
  structured
• web-based designs were dramatically different
  cool designs, hot images, attention-grabbing
  layouts ? user preference
• more accurate prediction of user performance
  integrating with task frequencies and sequences ?
  layout appropriateness deal with buttons, boxes,
  lists
• Window Design
• Coordinating multiple windows
• coordinated windows windows appear, change
  contents, and close as a direct result of user
  actions in the task domain
• coordination a task concept that describe how
  information objects change based on user actions

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• Synchronized scrolling ? Hierarchical browsing
• opening/closing windows ? Saving/opening
  window state
• Image Browsing
• overview and detailed view -- zoom factor 5-30
  effective (additional intermediate view)
• side-by-side placement, zoom-and-replace approach
• fisheye views magnified focus area while
  preserving the context in a single display
• visually appealing, even compelling
• but changing distortion may be disorienting and
  zoom factor never exceeds 5
• Color
• use color conservatively
• limit the number of colors
• recognize the power of color as a coding
  technique
• ensure that color coding supports the task
• have color coding appear with minimal user effort
• place color coding under user control
• design for monochrome first
• consider the needs of color-deficient users
• use color to help in formatting
• be consistent in color coding

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14. Information Search and Visualization

• Introduction
• information retrieval ? information gathering,
  seeking, filtering, or visualization
• database management ? data mining from data
  warehouses and data marts ? knowledge networks or
  semantic webs
• information search using traditional UI hurdle
  for novice users and an inadequate for experts
• task objects are represented by interface objects
  in structured relational databases, textual
  document libraries, or multimedia document
  libraries
• task actions (browsing or searching) represented
  by interface actions (scrolling, zooming,
  joining, or linking
• Tasks specific/extended fact finding,
  exploration of availability, open-ended browsing
  and problem analysis
• Searching in Textual Documents and Database
  Querying
• SQL requires training, and even then users make
  frequent errors
• natural-language queries appealing but limited
  computer processing capacity
• form-fillin queries and query-by-example
• five-phase framework
• Formulation expressing the search ? source,
  fields, phrases, variants
• Initiation of action launching the search ?
  explicit, implicit initiation, dynamic query
• Review of results reading messages and outcomes
  ? sequence and cluster
• Refinement formulating the next step ? history
  buffer
• Use compiling or disseminating insight

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• Multimedia Document Searches
• image search -- query by image content (QBIC) ?
  search for distinctive features or search for
  distinctive colors
• Map search search by features
• Design or diagram search
• Sound search
• Video search
• Animation search
• Advanced Filtering and Search Interfaces
• filtering with complex Boolean queries
• automatic filtering
• dynamic queries
• faceted metadata search
• collaborative filtering
• multilingual searches
• visual searches
• Information Visualization
• the use of interactive visual representations of
  abstract data to amplify cognition
• visual-information-seeking mantra overview
  first, zoom and filter, then details on demand
• Data type by task taxonomy (TTT) and seven tasks
  (Box 14.2)

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• 1-D 1inear data
• in a sequential manner textual documents,
  dictionaries, alphabetical list of names
• interface-design issues include what fonts,
  color, size to use, and what overview, scrolling,
  or selection methods to provide for users
• 2-D map data
• maps, floor plans, newspaper layouts
• interface-domain features (size, color, opacity)
• user tasks to find adjacent items, regions
  containing items, paths between items and to
  perform the seven basic tasks
• 3-D world data
• molecules, the human body, and buildings
• users tasks typically deal with continuous
  variables such as temperature or density
• cope with the position and orientation when
  viewing the objects ? potential problems of
  occlusion and navigation ? overviews, landmarks,
  teleoperation, multiple views and TUI
• Multidimensional data
• n attributes in a n-dimensional space (dynamic
  two-dimensional scattergram)
• tasks include finding patterns, clusters,
  correlations, gaps and outliers
• three-dimensional scattergram (disorientation and
  occlusion)
• Temporal data
• items have a start and finish time, and that
  items may overlap
• finding all events before, after, or during time
  period and the seven basic tasks

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• Tree data
• Network data
• shortest or least costly paths connecting two
  items or traversing the entire network
• Overview task
• movable field-of-view box (zoom factors of 3 to
  30), fisheye strategy
• Zoom task
• Filter task
• Details-on-demand task
• simply click on an item to get a pop-up window
  with values of each of the attributes
• Relate task
• proximity, containment, connection, color coding
  highlighting
• History task
• history of actions to support undo, replay, and
  progressive refinement
• Extract task
• Challenges for information visualization