Critical Review of 'The Usability Metric for User Experience'

In 2010, Kraig Finstad published (in this journal) 'The Usability Metric for User Experience'-the UMUX. The UMUX is a standardized usability questionnaire designed to produce scores similar to the System Usability Scale (SUS), but with 4 rather than 10 items. The development of the questionnaire followed standard psychometric practice. Psychometric evaluation of the final version of the UMUX indicated acceptable levels of reliability (internal consistency), concurrent validity, and sensitivity. Critical review of this research suggests that its weakest element was the structural analysis, which concluded that the UMUX is unidimensional based on insufficient evidence. Mixed-tone item content and parallel analysis of the eigenvalues point to a possible two-factor structure. This weakness, however, is of more theoretical than practical importance, given the overall scale's apparent reliability, validity, and sensitivity.