Expected Usability Magnitude Estimation

Abstract

Usability measures typically focus on actual user experiences while largely ignoring the impact of user expectations. User expectations provide insight into overall usability, user satisfaction, and priority of usability problems. Beyond test results, communicating user expectations can offset the negative connotation many development teams have of usability by showing examples where expectations are exceeded. This paper describes the expected Usability Magnitude Estimation (UME) method to assess user expectations in usability tests. The method is more valid, robust, and theoretically based than existing methods. It allows measurement of expectations that is easy to administer, simple to analyze, and provides actual and expected usability ratings along the same ratio scale of usability. Expectation data is used to classify tasks into empirically derived design strategy groupings based on refined theory. Overall, the method positively contributes to usability results and development team relationships.