Evaluation Through Expert Analysis U U U

Cognitive Walkthrough Similar to a code walkthrough. Identify difficulty areas. Any stage in the design process. Relatively cheap.

What You Need System prototype Description of task Complete list of actions Knowledge of intended users

Four Questions Effect of action = user’s goal? Visibility of available actions User knowledge of actions Understandable feedback

Heuristic Evaluation Method of evaluating the system Method of finding usability problems Discount usability technique Needs 3 to 5 evaluators

10 Heuristics 1. Visibility of system status 2. Match between system and real world 3. User control and freedom 4. Consistency and standards 5. Error prevention

Cont… 6. Recognition rather than recall 7. Flexibility and efficiency of use 8. Aesthetic and minimalist design 9. Help users recover from errors 10. Help and documentation

Model-based evaluation A third expert-based approach is the use of models. GOMS (goals, operators, methods and selection)

Cont… Design rationale provides a framework in which design options can be evaluated. Dialog models can also be used to evaluate dialog sequences for problems.

The End