ABSTRACT

With the universality of mobile devices, more and more types of apps have appeared in accordance with consumers’ habits and different consumer groups. How to better match consumers’ habits and adapt quickly to change in terms of an apps functions and uses is a topic that is now being researched in greater depth in both academia and industries. This study used the messaging software Top-Call and SunlineApp by SunlineNP Telecom, a Type II telecommunications business, as samples to test their usability. TopCall is an older type of messaging software that was designed by SunlineNP Telecom, and SunlineApp is a newly designed app that was based on TopCall following the optimization of usability design in this study. This study aimed to explore the two types of software by using sample testing. Furthermore, it aimed to understand how apps nowadays optimize their interface design in order to better match consumers’ habits and improve user experience, and also to discover the before/after differences by the use of optimization experiments. The methodology that was used to test usability in this study was performance measurement. Typical tasks were designed, and users were tested on their operating time and the number of errors. Following the tests, the Systematic Usability Scale (SUS) was administered. After 20 subjects had operated the two types of app, the findings were: (1) better efficiency: the average time taken for a user to complete a single task decreased by 27 seconds at most, (2) better error proofing: the number of errors after completing tasks decreased by 54 percent at most, and (3) greater satisfaction: the average SUS score of the subjects improved from 29 to 72, a rise of 2.4 times. SunlineApp was found to be better than TopCall in the three indicators of usability testing, which showed that user satisfaction grew after the usability of SunlineApp was improved by the optimization design in this study.