A Quantitative Evaluation of Usability in Mobile Applications: An Empirical Study

Developing high quality applications, in adequate time and low cost is the goal of using software engineering methods and processes. Over the years, a focus on usability has shown itself to be one of the cheapest and easiest ways to improve a system's quality (or more precisely, the user's perception of quality). This quality factors is an important issue in user experience of mobile applications. In this paper, our research question is if using various types of user guide affects the usability of mobile applications. Our contribution in this paper is focusing on quantitative evaluation via logging the user interaction automatically. Based on this point of view, the research question is defined in more details: if using animation or text user guide results a significant difference on timing factors of usability including task completion time, time spent using help, and time used to search a button to perform a specific function. To answer this question, we design an empirical study. In this study, a mobile application has been selected and two types of user guide (animation and text) are generated. To run the study, 68 audiences are participated that are divided into two independent groups. They use two versions of the mobile application: One contains an animated user guide for a functionality, while the other application has a text user guide that describes the same functionality. The activities of the users are logged and used to measure selected time factors. Applying the Mann-Whitney U Test on the results shows that animation user guide does not improve the time used to search a button to perform a specific function significantly, but it makes 76.9% improvement in time spent using help and 32.4% in task completion time. In the other words, the result of this study shows that animation user guide decreases the total time of task completion, and consequently it increases the usability of the function in our case study.