Usability Evaluation Methods

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Usability Evaluation Methods

• Computer-Mediated Communication
• Lab week 10 Tuesday 7/11/06

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Aspects of interaction design

• The intended user(s)
• The intended functionality
• Navigation design
• Local structure
• Global structure hierarchical organization
• Global structure dialog
• Screen design and layout
• Visual tools for layout
• User action and control
• Appropriate appearance

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Evaluation
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Usability tests and Expert evaluations

• Experienced designers have attained the wisdom
  and humility to know that extensive testing is a
  necessity (Shneiderman 1998)
• Goals
• Assess extent and accessibility of functionality
• Assess users experience of the interaction
• Identify any specific problems
• Place
• laboratory
• field
• Moment
• during design life cycle

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Types of evaluation methods

• Experts
• Analysis
• Review
• Model

• Users
• Experiment
• Observation
• Questions
• Registration

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Evaluation through expert analysis

• Cognitive walkthrough
• Prototype of system
• Representative task description
• List of actions needed to complete task
• Who are the users, experience and knowledge
• For each action, 4 questions
• Is the effect of the action the same as the
  users goal at that point?
• Will users see that the action is available?
• Once users have found the correct action, will
  they know it is the one they need?
• After the action is taken, will users understand
  the feedback they get?

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Evaluation through expert analysis

• Heuristic evaluation
• Nielsens ten heuristics
• Model-based evaluation
• GOMS
• Using previous studies
• Results of experiments

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Evaluation through user participation

• Observational techniques
• Think aloud and cooperative evaluation
• Protocol analysis
• Post-task walkthroughs
• Query techniques
• Interviews
• Questionnaires
• Monitoring physiological responses
• Eye tracking
• Physiological measurements
• Experimental evaluation
• Participants
• Hypotheses
• Experimental design
• Statistical measures

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Questionnaires

• SUMI http//www.ucc.ie/hfrg/questionnaires/sumi/
• QUIS
• http//www.lap.umd.edu/QUIS/index.html