CS459559 HumanComputer Interaction

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CS459/559Human-Computer Interaction

• Introduction to Usability
• and the User Experience
• 8-29-2007
• Prof. Searleman, jets_at_clarkson.edu

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Outline

• Cheers and Jeers
• good bad designs
• Usability User Experience
• HW1 posted, due next Wednesday, 9/5/07
• Activity Fair tonight, 7 8 pm, Cheel Arena

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Recap

• HCI has moved beyond designing interfaces for
  desktop machines
• About extending and supporting all manner of
  human activities in all manner of places
• Facilitating user experiences through designing
  interactions
• Make work effective, efficient and safer
• Improve and enhance learning and training
• Provide enjoyable and exciting entertainment
• Enhance communication and understanding
• Support new forms of creativity and expression

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Examples of bad and good design
Cheers Jeers class exercise
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Current Clarkson Webpage
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Peoplesoft
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What is involved in the process of interaction
design

• Identifying needs and establishing requirements
  for the user experience
• Developing alternative designs to meet these
• Building interactive prototypes that can be
  communicated and assessed
• Evaluating what is being built throughout the
  process and the user experience it offers

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Core characteristics of interaction design

• Users should be involved through the development
  of the project
• Specific usability and user experience goals
  need to be identified, clearly documented and
  agreed at the beginning of the project
• Iteration is needed through the core activities

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Why go to this length?

• Help designers
• understand how to design interactive products
  that fit with what people want, need and may
  desire
• appreciate that one size does not fit all
• e.g., teenagers are very different to grown-ups
• identify any incorrect assumptions they may have
  about particular user groups
• e.g., not all old people want or need big fonts
• be aware of both peoples sensitivities and their
  capabilities

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Are cultural differences important?

• 5/21/1960 versus 21/5/1960?
• Which should be used for international services
  and online forms?
• Why is it that certain products, like the iPod,
  are universally accepted by people from all parts
  of the world whereas websites are reacted to
  differently by people from different cultures?

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Anna, IKEA online sales agent

• Designed to be different for UK and US
  customers
• What are the differences and which is which?
• What should Annas appearance be like for other
  countries, like India, South Africa, or China?

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Usability and The User Experience
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What Is Usability?
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How Should We Measure Usability?

• Bottom line is whether the users got what they
  wanted, i.e., is the client satisfied
• Practically speaking, need to break this down so
  that we can operationalize our objectives
• Textbook definition
• The quality of an interactive computer system
  with respect to ease of learning, ease of use,
  and user satisfaction
• Can the users do what they want to do in a
  comfortable and pleasant fashion?

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Usability Goals

• Enable you to set goals before starting the
  project
• Technology can then be measured against usability
  goals during evaluations
• Provide ways of comparing different designs

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Usability UIDE

• Effectiveness
• accuracy and completeness with which specified
  users can achieve specified goals in a given
  environment
• Efficiency
• resources required to achieve these goals
• Satisfaction
• comfort and acceptability of the system to its
  users others affected by its use

UIDE refers to the textbook User Interface
Design Evaluation
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Usability goals ID2

• Effective to use
• Efficient to use
• Safe to use
• Have good utility
• Easy to learn
• Easy to remember how to use

ID2 refers to the textbook Interaction Design,
2nd Edition
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Effectiveness

• How accurately and completely users can
  accomplish tasks
• Examples
• If looking for particular information on a
  website, can the user find correct and complete
  information?
• Given information on University websites, could
  you learn about the meeting time and place for
  this class and the textbook you needed to buy?

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Effectiveness

• Choice of providing training or not
• Consider task completion unsuccessful if not
  completed by a reasonable amount of time
• Challenging to define for creative tasks
• Directly linked to user needs

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Efficiency

• How quickly can users complete tasks?
• It may be evaluated through time, the number of
  steps required, or some other measure
• How long does it take you to find the roster of
  the Universitys mens and womens hockey teams?

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Efficiency

• A similar measure is how long users think it
  takes to complete a task
• Good design users think it takes less than
  actual time
• Poor design users think it takes longer than
  actual time
• Try to see normal, not hurried operation

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Safety

• Avoid danger while operating technology
• Avoid dangerous situations caused by interaction
  with technology
• Provide users quick ways to recover
• Examples
• BlackBerry thumbs (injury due to repeated use)
• Mizuho trade blunder

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Safety

• Sometimes difficult to evaluate
• How could a criminal use the technology?
• Privacy
• Data security

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Utility

• Does system provide enough functionality for
  users to accomplish necessary tasks?
• Closer to software engineering testing
• Example
• Does the CS Departments website offer sufficient
  information on how to complete a degree?

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Utility

• Beware of creeping featurism
• Adding rarely used features can affect usability
  for most users
• Easy access to commonly used features
• Access to rarely used features for experts

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Learnability

• how easy a system is to learn how to use
• question How easy is it and how long does it
  take (i) to get started using a system to perform
  core tasks and (ii) to learn the range of
  operations to perform a wider set of tasks?

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The Ten-Minute Rule(Nelson, 1980)

• novice users should be able to learn how to use a
  system in under 10 minutes
• when is the 10-minute rule appropriate? when
  inappropriate?

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Memorability

• how easy a system is to remember how to use, once
  learned
• question What kinds of interface support have
  been provided to help users remember how to carry
  out tasks, especially for systems and operations
  that are used infrequently?

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Usability Shneiderman

• time to learn
• speed of performance
• rate of errors by users
• retention over time
• subjective satisfaction

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Usability Shackel

• effectiveness
• how fast, how error-free
• learnability
• how much training, practice, re-learning
• flexibility
• is the interface still effective if the tasks
  and/or the environment changes?
• attitude
• Do users like the system? Is it tiring,
  rewarding?

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Activity on usability

• How long should it take and how long does it
  actually take to
• use a VCR to play a video?
• use a VCR to pre-record two programs?
• use an authoring tool to create a website?

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The User Experience

• How a product behaves and is used by people in
  the real world the way people feel about it and
  their pleasure and satisfaction when using it,
  looking at it, holding it, and opening or closing
  it
• every product that is used by someone has a user
  experience newspapers, ketchup bottles,
  reclining armchairs, cardigan sweaters.
  (Garrett, 2003)
• Cannot design a user experience, only design
  for a user experience

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Why was the iPod user experience such a success?
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User experience goals

• satisfying aesthetically pleasing
• enjoyable supportive of creativity
• engaging supportive of creativity
• pleasurable rewarding
• exciting fun
• entertaining provocative
• helpful surprising
• motivating enhancing sociability
• challenging emotionally fulfilling
• boring annoying
• frustrating cutsey

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Next Time

• More on the User Experience

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Key Points

• users should be involved through the development
  of the project
• specific usability and user experience goals
  need to be identified, clearly documented and
  agreed at the beginning of the project
• iteration is needed through the core activities