A Usability Score for Mobile Phone Applications Based on Heuristics

Mobile phones are becoming the most widespread personal consumer device. Yet, offering mobile access anywhere, anytime for anybody poses new challenges to usability. So far there is little research on how to customize usability heuristics to the specific characteristics of mobile phone applications. Therefore, this article presents a set of tailored usability heuristics based on a systematic literature review. In order to facilitate the usage of these heuristics, the authors design and validate a measurement instrument (checklist) and scale. The checklist has been validated through an empirical study in which the results of 247 heuristic evaluations have been statistically analyzed using Item Response Theory. Based on the results, the measurement items have been calibrated and a standardized measurement scale has been constructed. The results can be used to measure usability of mobile phone applications from early on in the design process, and, thus, facilitate evaluations in a cost-effective way.