Operationalise criteria Can the attribute be ”measured”? Define a scale Define acceptance or target criteria
Operationalise criteria: Example 1 Effective Number of tasks performed correctly Scale: Summarise the number of tasks performed and divide by number of possible tasks Criteria: All users must perform all important tasks
Operationalise criteria: Example 2 Efficient The effort users have to invest in performing the task Scale: the more effort, the less efficient Criteria: less effort than old product
http://zing.ncsl.nist.gov/hfweb/proceedings/etgen-cantor/ Operationalise criteria: Example 3
Student tasks Can you think of any potential usability problems with your product? What is the most important usability attribute for your product?