Chp.2: Components of HCI

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Chp.2 Components of HCI

• How to achieve HCI goal of developing or
  improving systems (safety, utility,
  effectiveness, efficiency, usability, etc.) AND
  make sure system integrates well into
  organizational settings in which its used?
• A multi-disciplinary perspective is used --
  analyze problems from different perspectives,
  including consideration of range of factors
• organization (training, job design, politics)
• environment (noise, lighting, ventilation)
• health safety (stress, headaches, fatigue)
• human comfort factors (motivation, enjoyment,
  satisfaction, proficiency)
• user interface (input, output, color, graphics,
  etc.)
• task factors (easy, complex, etc.)
• constraints (cost, timescales, budgets, staff,
  equipment)
• system functionality (hardware, software,
  application)
• productivity factors (ouput levels, cost,
  production time)

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Chp.2 Components of HCI

• Four examples (3 from old text, 1 from new text)
• airline ticket reservations
• supermarket checkout
• paper interface (should be PDA)
• cell phones
• Each case considered in terms of a range of HCI
  factors
• human (e.g., staff, customer)
• user interface
• work activity
• organization
• comfort
• productivity
• etc

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Chp.2 Components of HCI

• Airline reservation system
• Before
• customer went to travel agency
• gave desired destination and travel times to
  agent
• agent called airline
• check with customer to see if times ok
• if seats/time not ok, repeat
• ticket accounting agents fills out paper forms,
  sends to airlines bi-weekly

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Chp.2 Components of HCI

• Airline reservation system
• Now
• customer goes on-line
• use types in desired times, destination
• wait for search engine
• like times, prices? if not repeat.
• press buttons to give payment info
• ticket accounting issued electronically, airline
  dB updated immediately

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Chp.2 Components of HCI

• Airline reservation system
• HCI factors
• human (staff) possibly out of work
• human (customer) enjoys immediacy of seat
  selection, but has to do more work him/her-self
• UI keyboard, web forms, etc.
• work activity more work placed on user
• organization training needs - user has to know,
  learn how to use system impersonal (some people
  prefer F2F interaction with travel agent)
• comfort use has to have computer, may interfere
  with current task
• productivity user has to take time away from
  other tasks

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Chp.2 Components of HCI

• Supermarket checkout
• Goal automate pricing/inventory procedures
• Infrastructure requirements
• all items in store must be barcoded
• dB must exist to handle purchases/pricing
• need scanning systems installed

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Chp.2 Components of HCI

• Supermarket checkout
• Discussion
• What are effects on
• user (staff)?
• user (customer)?
• is the user interface easy to learn/use?
• how are problems handled (e.g., mis-scanned
  product, incorrect price)?
• what is the work activity - is training required?
  for whom? (customer, staff, both?)
• comfort how is cashier affected?
• system what is needed (expensive? difficulty of
  install?)
• productivity and spin-off factors is process
  more streamlined? What about marketing analysis
  (BiLo card)?

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Chp.2 Components of HCI

• Xerox Parcs paper user interface (PalmPilot more
  appropriate)
• Discussion
• What are effects on
• technology what is required for development of
  PDA such as the PalmPilot (hardware, software)?
• what is the user-interface easy to learn?
• organization is users world better organized?
• comfort easy to handle, transport?

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Chp.2 Components of HCI

• Cell phones (theyre great to pick on right now
  )
• Discussion
• major usability drawbacks
• restricted access (getting better)
• very small LCD screen
• mostly text-based (image/video based starting to
  appear, however, is this more expensive, i.e.,
  pay for time to download?)
• assumptions used
• people want to use device while mobile
• people want to interact with info while on the
  move
• users will trade screen real estate for
  information (???)
• phones will offer comparable interaction to PCs
  (???)

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Chp.2 Components of HCI

• In evaluating multiple factors, various
  disciplines contribute to HCI
• Computer Science (dB, O/S, AI, Grahpics, )
• Psychology (Cognitive, social, organizational)
• IE (Ergonomics, human factors)
• Design
• Anthropology
• Sociology
• Philosophy
• Linguistics

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Chp.2 Components of HCIComputer Science

• Mostly system/technology level
• programming languages, compiler, etc.
• O/S
• Networking
• WWW
• GUI toolkits and window managers
• multimedia
• graphics
• VR (new devices, incl. sensors, effectors,
  haptics)
• Application use whatever devices/techniques suit
  the application

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Chp.2 Components of HCICognitive Psychology

• Understanding human behaviour, underlying mental
  processes, and capabilities and limitations
  thereof
• perception
• attention
• memory
• learning
• thinking
• problem solving
• Application apply principles to design, e.g.,
  memory and attention are limited, dont clutter
  UI with gt 7 /- 2 things at a time

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Chp.2 Components of HCISocial and
Ogranizational Psychology

• Understanding human behaviour in social contexts
• individuals influence on another
• individuals influence on group (e.g., leadership
  qualities, or weakest link)
• groups influence on individual (e.g., peer
  pressure)
• relationship between different groups (e.g.,
  different preferences, tastes, as in high school
  jocks, geeks, etc.)
• Application consider how computers affect
  oranizations, groups of people

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Chp.2 Components of HCIErgonomics Human
Factors

• Maximize operators safety, efficiency,
  reliability, performance, satisfaction, etc.,
  e.g., ergonomic cockpits, office furniture, etc.
• Application evaluate devices/interaction from
  ergonomic perspective, e.g.,
• VDUs (monitors) that minimize eye strain
• devices that dont cause carpel tunnel
• VR simulators that promote training, test human
  performance

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Chp.2 Components of HCILinguistics

• Study of language, understanding structure
  (syntax) and meaning (semantics)
• Application apply to human-interface dialogue
  (how does system speak to user)
• natural language interface (voice recognition,
  e.g., e.Digitals MXP 100 MP3 player)
• query languages (dB)
• internationalization (locales)

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Chp.2 Components of HCIPhilosophy, Sociology,
Anthropology

• Soft science?
• Usually considers social implications of IT,
  e.g.,
• are workers being displaced?
• are we becoming less social (more time in email
  than F2F)?
• Increasingly important especially in domains such
  as CSCW, I.e., how do people interact,
  communicate, collaborate
• Application apply to computer-supported
  human-human interface dialogue (how do humans
  communicate)
• eye-to-eye contact?
• deictic (look at that) references?
• e.g., Hiroshi Ishiis TeamWorkstation maintained
  eye contact in video telephony applications

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Chp.2 Components of HCIConceptual Model of HCI

• HCI is neither the study of humans, nor of
  technology, rather it is the bridging between the
  two (to paraphrase Terry Winograd)
• Design concept know how to make transition from
  what can be done technologically to how to make
  it usable for users in their environment
• Lowest level select most appropriate input (VR,
  pen, mouse) and output device (video, speech,
  text), then decide on interaction style (natural
  language, GUI, VR, multimedia), knowing human
  psychology and particular human characteristics
  relevant to task at hand (e.g., for text display,
  dont use green on red)

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Chp.2 Components of HCIConceptual Model of HCI

• To develop a conceptual model involves
  envisioning the proposed product, based on users
  needs and other identified requirements
• one particularly useful HCI technique is to
  develop prototypes
• Key aspect task-based analysis---what will users
  be doing when carrying out their tasks?
• Once interaction requirements have been defined
• consider look and feel of interface
• consider interface metaphor (e.g., desktop)
• consider conceptual metaphor

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Chp.2 Components of HCIConceptual Models

• Conceptual models based on activities
• instructing (e.g., a system to do something
  cmds)
• conversing (e.g., with system help page, menu)
• manipulating and navigating (e.g., direct manip)
• exploring and browsing
• (not mutually exclusive)
• Problems
• instruction set prone to (syntax) errors?
• conversations prone to semantic errors?
• direct manipulation (clickdrag) too literal?
• exploring and browsing how to allow navigation?

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Chp.2 Components of HCIConceptual Models

• Conceptual models based on objects
• spreadsheet (killer app based physical ledger)
• Quicken (paper checks and registers
• Conceptual models may require a mix of models of
  objects and actions
• but use caution this may lead to numerous ways
  of doing things, e.g.,
• speak delete file (conversation?)
• press CTRL-D (command)
• drag file to trash (direct manipulation)
• this may result in steeper learning curve

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Chp.2 Components of HCIConceptual Models

• Interface metaphors
• another way of conceptualizing interface
• can be based on actions, objects, or both
• usually based on combination of familiar
  knowledge with new concepts (using analogies to
  bridge gap between)
• Examples
• desktop metaphor (this ones a popular example)
• dragging a file to trash (same as real action)
• highlighting text

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Chp.2 Components of HCIConceptual Models

• Interaction paradigms
• a more general abstraction of conceptual model
• a particular philosophy (prone to shifting )
• examples
• applications for the desktop GUI, WIMP
• now moving beyond the desktop, e.g.,
• Body-Area Network (BAN)
• ubiquitous computing (embedded tech.)
• pervasive computing
• wearable computing
• AR / VR
• tangible user interfaces
• haptic interfaces
• attentive environments (attentive displays)

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Chp.2 Components of HCIDesign process

• 4 components
• people
• work (the task)
• environment (physical, organizational, social)
• technology
• The HCI design process not quite as linear as
  software engineerings waterfall model
• Key differences
• user-centered design involve users as much as
  possible
• integration of multidisciplinary knowledge
• iterative design periodically check with user

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Chp.2 Components of HCIDesign process

• Inolving users
• decide who end user is, how product will be used,
  made, sold, marketed
• observe current user practices - leads to system
  requirements (how can current practice be
  improved?)
• can use psychological models of human, e.g.,
  follow test such concepts as Fitts Law
• include user representatives on team
• end users
• management
• marketing personnel
• graphic designers, etc.

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Chp.2 Components of HCIDesign process

• Incorporating interdisciplinary knowledge
• computer science (AI, graphics, O/S, dB, etc.)
• psychology
• human factors
• linguistics
• philosophy
• sociology
• anthropology

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Chp.2 Components of HCIDesign process

• Iterate the design process
• use the Star model featuring iterative
  evaluation (as center of star)
• components
• requirements specification
• task analysis / functional analysis
• conceptual design / formal design
• implementation
• prototyping