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Human-Computer Interaction

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					Human-Computer
Interaction
Introduction and Overview




                 ISyE 4009   1
What is Human-Computer
Interaction?
A student’s incorrect answer…
    “human-computer interaction is explained
    adequately in the movie Zoolander (the
    part where Hansel and Derek realize the
    files and “in” the computer”
A little closer…
     “human-computer interaction is getting
  people to work well with machines”
                    ISyE 4009                 2
What is Human-Computer
Interaction?
   User     whoever is trying to get a job done
    using technology
    – Individual user
    – Group of users working together
    – Sequence of users in an organization
   Interaction   any communication between
    a user and computer
    – Direct – dialog with feedback and control
      throughout the performance of the task
    – Indirect – may involve background or batch
      processing
                         ISyE 4009                 3
What is Human-Computer
Interaction?
   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
   Human-computer interaction has science,
    engineering, and design aspects.
                    (ACM SIGCHI 1992, from Preece et al, p.7)


                        ISyE 4009                           4
What is Human-Computer
Interaction?
   HCI is concerned with:
    – the joint performance of tasks by humans and machines
    – the structure of communication between human and
      machine
    – human capabilities to use machines (including the
      learnability of interfaces)
    – algorithms and programming of the interface itself
    – engineering concerns that arise in designing and building
      interfaces
    – the process of specification, design, and implementation of
      interfaces
    – design trade-offs


                              ISyE 4009                         5
Components of HCI
         Human Users                                Computer Systems
   Creative                                 Non-Creative (yet?)
   Inductive                                Deductive
   Flexible                                 Inflexible
   Dynamic/ Learning abilities              Static Development
   Spatial                                  Numerical
   Fast at Reasoning/Slow at                Poor at Reasoning/ fast and
    Calculation                               accurate at calculation
   Large long term memory                   Limited memory but greater
    versus limited short term                 than short term human
                                              memory
                            Interaction

                                  ISyE 4009                             6
Terminology
   Ergonomics
    – Traditionally ergonomics is primarily concerned
      with the physical characteristics of machines,
      and how they affect user performance
    – European
   Human Factors
    – Primarily concerned with the performance of one
      or more persons in a task-oriented environment
      interacting with equipment, other people, or
      both
    – United States

                          ISyE 4009                     7
Terminology

   Human-Integrated Systems
    – A combination of one or more humans
      and one or more physical components
      interacting to bring about from given
      inputs, some desired output
   Man-Machine Interaction
   Human-Computer Interaction

                      ISyE 4009               8
Terminology

   System
    – Any organized assembly of resources and
      procedures united and regulated by
      interaction or interdependence to
      accomplish a set of specific functions
    – Can someone paraphrase?
    – A system is a collection of elements that
      function together to achieve some
      objective
                      ISyE 4009                   9
 Terminology

    Machines (In terms of this course)

                     Simple                        Complex
  Not Time-        Telephone              Some Information Systems
   Critical         Door                     Programmable VCR
  (Usually)     Pencil Sharpener
                 Emergency Door            Fighter Aircraft Cockpits
   Often        Basic Car Controls             Nuclear Reactor
Time-Critical   Fire Extinguisher         Other Information Systems



                              ISyE 4009                                10
History of HCI
   The term human-computer interaction has
    only been in widespread use for a little over
    a decade
   WWII started the movement towards
    studying the interaction between humans
    and machines
    – To produce more effective weapons
    – Correct accidents caused by human error in
      cockpits, following the growth of cockpit
      technology
                         ISyE 4009                 11
History of HCI
   Ergonomics research society was formed in 1949
   In the 1970s and early 1980, there was interest
    from psychologists in the information processing
    aspects of computer system design.
    – Topics such as the menu names and depth versus breadth
      in menu design were popular areas of study.
   In the early and middle 1980s, researchers became
    interested in usability issues in a single (not
    connected) computer system.
   In the late 1980s and 1990s, the powerful and
    personal computer became available.

                            ISyE 4009                      12
History of HCI
  Three systems that provide landmarks along this
evolutionary path are the Dynabook, the Star and
the Apple Lisa (Predecessor of today's Macintosh).

  In late 1990 and early 2000, the rapid growth of
Internet became a crucial field of HCI community.

 Today the field of HCI is comprised of a variety of
subfields including:
    mobile computers (i.e. cell phones, PDAs, etc.)
    smart houses (i.e. GT Aware Home)
    wearable computers
    augmented virtual reality
                              ISyE 4009                13
    and much more!
Who Contributes to HCI?

   Psychologists
    – Gives knowledge of user’s perceptual, cognitive,
      and problem solving skills
   Sociologists
    – Helps in understanding the wider context of the
      interaction; interaction as social activity
   Computer Scientists
    – Building and creating the necessary technology


                          ISyE 4009                      14
Who Contributes to HCI?

   Systems Engineers
    – Measure system workflow and efficiency
   Graphic Designers
    – Make systems aesthetically desirable
   Ergonomists
    – Interaction is physical as well as
      conceptual

                        ISyE 4009              15
Why is HCI Important?
   Computers are now widely used by people who
    may be experts in their particular field but are not
    computer experts.
    – Systems need to be much easier to learn and to use
   The cost of software is high and the competitive
    edge is more difficult to achieve.
    – The interface to a system might give it this edge.
   It is expensive to train users
    – A system which is easy and natural to use will save money
      since the training time will be kept to a minimum.
   The cost of human error can be high.
    – Systems that are transparent and easy to use ought to
      reduce the likelihood of error or at least to aid error
      recovery.
                              ISyE 4009                         16
General Principles of HCI
Design
   Consistency
   Physical Analogy
   Expectations and Stereotypes
   Ease of Learning Versus Ease of Use
   Avoiding Excess Functionality and
    Using Multiple paths
   Design for Progressive Disclosure and
    Graceful Evolution
                    ISyE 4009               17
Consistency
   Lack of consistency in system design results in…
    • User must develop a new mental model of the system
    • User rely on several different models during use

   Real projects involve a group effort in
    design/implementation
    • Graphical User Interfaces are no exception.
    • Specification is essential
    • GUI functionality should be consistent at every level

   Example
    Word processing - Deletion
    should be consistent at the letter/word/paragraph/text level.

                                ISyE 4009                           18
Physical Analogy

    Users often rely on physical analogies
    in modeling systems
    – This can be exploited
    – For example
        Users often compare word processing tools
         with type writers.
        A word processor design could exploit this by
         mimicking a typewriter

                         ISyE 4009                       19
Expectations and
Stereotypes
   Expectations from other domains can
    be exploited to facilitate learning.
    – For example:
    Traffic Lights           User Interface
       Red                      Alarm
       Amber                    Caution
       Green                    Safe

                     ISyE 4009                20
Ease of Learning versus
Ease of Use
   Ease of learning for novices often lowers ease of use for
    experts
     – Learning requires prompts which an expert can ignore
     – Learning limits functionality which an expert can exploit

   Steps must to taken to avoid these limitations.
     – Design for three levels of expertise: novices, intermediates,
       experts
     – Avoid & Prioritize Excess Functionality
     – Provide Multiple Paths

   Example:
     – Microsoft Paperclip “Intelligent Agent”


                                  ISyE 4009                            21
Multiple Paths

   Menu Bypass
    (keyboard short cuts/Expert Menus)
   Stacking and type ahead commands to
    bypass menus
   Input device options

Multiple path choice depends on the application & task

                         ISyE 4009                   22
Progressive Disclosure
and Graceful Evolution
Progressive Disclosure:
Increased Functionality modeled by expertise of User.

Graceful Evolution:
Smooth development of User from Novice to Expert.

   Make fundamental features easy to learn.
   Make frequently used functions quick to perform
   Encourage Experimentation
    – Consistency
    – Reversibility
   Use Defaults which can be later changed by expert.


                              ISyE 4009                  23
A Conceptual
Model for HCI




           ISyE 4009   24
HCI & Design

Rather than the traditional design
models adopted within software
engineering. HCI has adopted a design
model which aspires to incorporate the
following premises:
  – user centered
  – multi disciplinary
  – highly iterative
                         ISyE 4009       25
HCI & Design

   Involving Users:
    – This may range from observing users
      interacting with a system, to the use of
      psychologically based user modeling
      techniques, to the inclusion of
      representative users in the design team.
   Adopting an Iterative Design Strategy:
    – This attempts to ensure that appropriate
      knowledge has the opportunity for input at
      appropriate stages of the design cycle.
                       ISyE 4009                 26
Examples of Bad Design
Justification for learning about HCI




                   ISyE 4009           27
Things that don’t work
the way you expect..
         The lids on oatmeal containers were
         recently redesigned. The problem is that it
         looks like you can pick up the container by
         the lid, but you can't.
         Design suggestion
         The lid on the new-style container should
         not look like it could work as a "handle" to
         pick up the container. This might be done
         by: Not making the center of the lid set
         down in the top of the container so deeply.
         Removing the "handle" from the inside of
         the lid by curving the lip outward rather
         than inward.
             ISyE 4009                          28
Things that don’t work
the way you expect…
       How do you open the refrigerator?
       Apparently, the refrigerator door was designed so it
       could be hinged on either the left or the right side.
       Thus, handles were put on both sides. However,
       people only expect to see one handle on a
       refrigerator door. When the handle doesn't work,
       they assume the door is stuck or locked.
       Design suggestion
       It would be best to put a handle on the front of a
       refrigerator door so that it can be easily seen. On a
       reversible door with handles on both sides of the
       door, there should be a way of removing or
       concealing the handle on the hinged side. There
       should not be visible handles on both sides!

                   ISyE 4009                              29
Different things that are
too similar…
         The example shows two bottles containing different
         doses of insulin for treating diabetes. The bottle on
         the left contains Insulin R (for Regular Insulin),
         which acts relatively fast (4-6 hr period). The bottle
         on the right contains Insulin N (for NPH Insulin),
         which acts over a broader span of time and more
         slowly (12-18 hour period) The consequences of
         accidentally taking Insulin R instead of Insulin N at
         bedtime could cause a hypoglycemic reaction during
         the middle of the night and possibly cause death.
         Design suggestion
         Things that need to be distinguished from each
         other should differ by more than just a single
         feature.

                 ISyE 4009                              30
Things that don’t work
well together…
Hiding the radio
  This is the center console in a
  rental car showing how the cup
  holder is blocking access to the
  radio and cassette player. Its nice
  to have a cup holder, but this isn't
  a very good spot for it. Not only is
  it hard to use the radio, but if
  your drink spills, its going into the
  cassette player!
Design suggestion
  When you design an object, you
  need to consider the environment
  that it is used in.
                             ISyE 4009    31
Things that are hard to
see…
Push to start
  Part of the problem is that you may look for
  a "real" button to start the pump; a 3-D
  button. Whereas the actual button is flat.
  But probably the bigger problem was that
  there were so many stickers and decals on
  the gas pump that finding the start button
  was like finding a needle in a haystack.
Design suggestion
  Here are some things that would have made
  it easier to see the "push to start" button:
  Making it larger, Using colors that
  contrasted with the background, Removing
  some of the nearby stickers and decals,
  Making it more centrally located on the gas
  pump, Using a real 3-D button

                                 ISyE 4009       32
Class Activity

   Get into groups of 4 or 5
    – Preferably people you may want to work with on
      your course project
   As a group brainstorm as many systems
    that you think could benefit from usability
    testing and redesign
    – Examples: a particular webpage, kiosk, PDA
   Pick top three to present to the class

                         ISyE 4009                 33

				
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