A Study on the Impact of Mobile UX Smells on Efficiency

Abstract

User experience (UX) is widely regarded as a fundamental aspect for any digital product. In the recent years, the concept of UX smells has been studied as a systematic way to detect predefined user interaction issues and fix them with cataloged solutions. Most of the existing literature about UX smells focuses on desktop web applications, while there are only a few works addressing the mobile web. Although specific UX smells for mobile interactions have been proposed, there are no objective evaluations to determine their impact on the perceived UX. In this work, we evaluated 6 mobile UX smells (3 from the literature and 3 new proposals) with respect to efficiency in use. We conducted an online evaluation with 72 participants in 3 real websites, each one with a set of specific mobile UX Smells. In this evaluation, we compared each website to a refactored version of itself, i.e. with proposed fixes for each of the smells. To do this, we ran a between-subject experiment in which participants completed 10 everyday tasks on the websites while we measured their efficiency in terms of task completion time and number of user interaction events. We then compared these metrics in the default version of the websites vs. their refactored counterparts. Results showed that in most cases (15/20), either the time to complete the task or the amount of interaction events were higher in the presence of UX smells. Moreover, in 7 of the cases, the observed differences were statistically significant (p<0.05).