Chp.1: What is HCI?

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Chp.1 What is HCI?

• study of interaction between humans computer
• a methodology for
• modeling the human (e.g., perception, behavior)
• examining usability of computer programs,
  devices, techniques (in general doesnt have to
  be just computers, applies to anything man-made
  that humans use, e.g., cars, light switches,
  kettles, etc.)
• most imporantly HCI leads to DESIGN of interface
• past contributions physical devices (mouse,
  HMD), code (GUI toolkits, window managers)

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Chp.1 What is HCI?

• All about design - in the context of Computer
  Science, design of interface to back-end
  program
• Interface
• graphical (GUI)
• command-line (CLI)
• web-based
• VR, etc.
• Back-end
• Operating System (O/S)
• dB
• web site
• spreadsheet
• calculator

• word processor
• air traffic control display
• flight simulator
• nuclear plant
• automobile displays
• etc.

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Chp.1 What is HCI?

• Computer interaction
• almost ubiquitous (everywhere) chances are in
  whatever device you use, theres a chip in there
• e.g., typical day
• get up, press snooze on alarm clock (whats the
  interface on the clock?)
• drive to work (car interface)
• stop by ATM (ATM screen)
• after work, shopping (scanners at store)
• at home, eat dinner (microwave, stove)
• watch TV/DVD/VCR (various ent. devices)
• Interface design applies to all these computer
  interface is more obvious in some than in other
  examples

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Chp.1 What is HCI?

• Why bother with interface design?
• increasing productivity
• e.g., in the workforce employees with a better
  word processor will be more productive
• safety critical systems with poor interface may
  endanger lives
• e.g., ATC, operating room, nuclear plant
• commerce a good interface may sell a product
• e.g., todays hot items MP3 players, digital
  cameras, DVD players, etc.
• Key point users shouldnt have to think (much)
  about intricacies of interface to use the tool
  (INTUITIVE INTERFACE)
• e.g., ATM walk up to it, withdraw cash (fairly
  easy to use)

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Chp.1 What is HCI?

• Key principles of interface design
• visibility controls should be visible (e.g.,
  volume control on an MP3 player)
• affordance controls should map to their
  function, I.e., it should be obvious what each
  control (button, slider, etc.) does.
• controls should be intuitive, e.g., volume
  control use a vertical slider (up loud)
• feedback device should give user indication of
  its state (e.g., phone dial tone ready, busy
  signal, flashing light message or on hold)

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Chp.1 What is HCI?

• Examples of design, visibility, affordance,
  feedback

Fig.1 salt / pepper shakers which is which?
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Chp.1 What is HCI?

• Examples of design, visibility, affordance,
  feedback

Fig.2 which knob controls which burner?
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Chp.1 What is HCI?

• Examples of design, visibility, affordance,
  feedback

Fig.3 can I set the freezer / fridge temperature
independently?
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Chp.1 What is HCI?

• When designing a computer program
• think what capabilities program should have
• how is a user going to access those functions
• More formally,
• HCI is a discipline concerned with the design,
  evaluation, and implementation of interactive
  computing systems for human use and with the
  study of major phenomena surrounding them
• NOT just the creation of user-friendly programs
• Need to understand human processes (cognition,
  perception) and interaction protocol between
  human and computer

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Chp.1 What is HCI?

• HCI challenges
• continuous technological development, e.g.
• better / faster machines
• new languages, applications (web, internet, VR,
  multimedia, imaging, graphics, etc.)
• two concerns
• keep abrest of technology (e.g., SIGCHI)
• marry good HCI with effective use of technology
  (I.e., make sure both are good the back-end
  program works and the interface is good)

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Chp.1 What is HCI?

• HCI Goals
• production of usable, safe, and functional
  systems
• development or improvement of systems (including
  computing systems), with respect to
• safety
• utility (functionality, what system does)
• effectiveness (is it good at what it does)
• efficiency (in case of programming, speed, memory
  utlization, etc.)
• usability (key concept in HCI make system easy
  to learn and use)
• system consider complete environment, not just
  hardware or software, but people

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Chp.1 What is HCI?

• Examples of not very usable systems
• complicated telephones
• do you use all the features (e.g., multi-party
  conf. calls, call forwarding, call-waiting,
  etc.)?
• wristwatch
• how often do you use its extended features
  (time zone, stopwatch, alarm, countdown timer,
  etc.)
• Examples of very usable systems
• scissors
• intuitive how to use, mainly because it mostly
  has just one application

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Chp.1 What is HCI?

• Underlying HCI belief people come first a
  computer is just a tool, a means to accomplish
  some task, e.g.,
• writing a paper
• communicating with friends
• designing a landscape
• preparing income taxes
• cataloging, organizaing, printing pictures
• desinging roads, bridges, airplanes, cars, etc.
• For good design, need knowledge of humans and
  technology
• often need multi-disciplinary teams (e.g., Comp.
  Sci, Psychology, IE, Arts, etc.)

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Chp.1 What is HCI?

• Evolution of HCI
• 70s--80s psychologists interested in
  information-processing aspects of computer as
  analogy to mental processes (e.g., modeling brain
  as a computer, connectionist network, associative
  memory, etc.)
• various HCI studies testing menus (depth vs.
  breadth), usability of single-user computer
• 80s--90s examining more powerful PCs,
  workstations, communication (e.g. email),
  multimedia (e.g., imaging, visualization, data
  mining), VR (presence), group work (CSCW)

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Chp.1 What is HCI?Evolution of HCI three
landmark systems

• Dynabook
• Alan Kay, Xerox Parc
• one of first laptops (book-sized PC)
• Star
• Xerox Parc
• desk-sized system
• high-res display, graphics, icons
• mouse mapped to 2D desktop on screen
• Apple Lisa
• based to some extent on Dynabook Star
• precursor to Macintosh
• WIMP Windows, Icons, Menus, Pointer
• introduction of desktop metaphor
• GUI, WYSIWYG word processor

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Chp.1 What is HCI?Evolution of HCI Main
considerations

• All HCI takes place in social organizational
  context
• Application design is geared towards specific
  purposes, dividing tasks between human and
  machine
• To adapt application to human, need to know
  something about human psychological and
  physiological abilities and limitations
• human info processing limited attention, memory
• language linguistics, verbal comm.
• communication methods of, body language,
  emoticons, etc.
• interaction human-to-human, e.g., turn-taking
• ergonomics carple-tunnel syndrome, eye strain,
  fatigue,

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Chp.1 What is HCI?Evolution of HCI Main
considerations

• To create successful computer application, need
  to know something about capabilities and
  limitations of computer
• input devices, e.g., keyboard, mouse, camera,
  microphone, sensors, etc.
• output displays, graphics, sound, etc.
• dialogue techniques, genre, style what how to
  communicate to user, e.g., state of system,
  output (visualizations, charts, numbers, etc.),
  what colors to use, animation speed, etc

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Chp.1 What is HCI?Discussion

• Can you think of examples of
• very usable systems
• not so usable systems (are there any devices that
  appear to be confusing to people)? How can they
  be improved?
• Can you think of examples of
• very usable computer programs
• not so usable computer applications? How can
  they be improved?
• ASSIGNMENT 1 collect at least 3 examples
  (pictures) of not so usable systems, e.g.,
  door, whatever, doesnt have to be computer
  program

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Chp1 Goals of System Engineering

• Functionality
• Reliability, availability, security, data
  integrity
• Standardization
• common UI features (e.g., WIMP)
• Integration
• of multiple components/modules (libs)
• Consistency
• common action sequences (e.g., File-gtOpen)
• Portability
• e.g., Mac OS X, Linux, Windows

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Chp.1 Goals of UI Design

• Human factors central to evaluation
• Learnability (time to learn)
• Performance
• Human error (rate of errors by users)
• Retention (easy to use?)
• Satisfaction (subjective)

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Chp.1 Human Modeling

• Human cognitive and perceptual abilities
• Short-term memory
• Long-term memory and learning
• Decision making
• Attention and set (scope of concern)
• Search and scanning
• Time perception
• Personality differences
• Cultural diversity
• Universal accesibilty (users with disabilities)
• Elderly users