Usability Evaluation Methods

1. Usability Evaluation Methods Computer-Mediated Communication Lab week 10; Tuesday 7/11/06

2. 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 Usability Evaluation Methods

3. Evaluation Usability Evaluation Methods

4. 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’ Usability Evaluation Methods

5. Experts Analysis ‘Review’ Model Users Experiment Observation Questions Registration Types of evaluation methods Usability Evaluation Methods

6. 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 user’s 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? Usability Evaluation Methods

7. Evaluation through expert analysis • Heuristic evaluation • Nielsen’s ten heuristics • Model-based evaluation • GOMS • Using previous studies • Results of experiments Usability Evaluation Methods

8. 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 Usability Evaluation Methods

9. Questionnaires • SUMI: http://www.ucc.ie/hfrg/questionnaires/sumi/ • QUIS: http://www.lap.umd.edu/QUIS/index.html Usability Evaluation Methods