Aportaciones para la mejora de la usabilidad en aplicaciones móviles de comunicación social

Abstract

This Dissertation should be placed within the exponential growth in the use of mobile instant messaging applications (so-called MIM apps) for modern mobile devices (simply called smartphones) and motivated by several scientific studies that point out the usability problems that this type of applications present, in addition to the special characteristics of smartphones (e.g., reduced screen sizes, usage limited by batteries, reduced forms of interaction, etc.) that makes these modern technological devices different from traditional web pages accessed from desktop computers (systems in which usability has been extensively studied). To improve the usability of MIM applications, this research has been carried out within several phases. Firstly, a systematic usability evaluation has been performed (among others, through a formal definition of the main functionalities that define a MIM application and with the usage of usability inspection methods, that is, task analysis and heuristic evaluation) of the MIM applications that could be found currently in the markets of the two main mobile platforms (i.e., iOS and Android). As a result of this evaluation, along with usability problems detected on both platforms, a set of usability recommendations has been proposed to be applied in the design and implementation phases of MIM applications. Following this phase of systematic evaluation and proposal of recommendations, a MIM application prototype has been created on the Android platform that incorporates said set of usability recommendations. The prototype has been evaluated with usability inspection methods (i.e., task analysis and heuristic evaluation methods, that is, the same methods used in the initial systematic usability evaluation) to, after satisfactory evaluation results, research proceed to a controlled experiment with real users (user performance and user satisfaction have been measured). In this experiment, selected participants have carried out a series of activities with the aforementioned prototype and, in addition, with a group of existing MIM applications (i.e., MIM apps with good usability results derived from initial evaluations). This final phase has resulted in the validation of the proposed recommendations as usability guidelines to be used in this type of application. This research presents, in addition to (1) proposal and validation of the usability recommendations to be applied in the design of mobile instant messaging applications, some additional conclusions as a result of this research: (2) formal definition of the main functionalities that define what a mobile instant messaging application is, (3) confirmation of the actual presence of usability problems in current MIM applications, (4) confirmation that good interface designs have a positive effect on user performance with this type of applications, and (5) exposure that users’ close contacts are the ones who act as the anchor for the users to remain in a given MIM application (despite having disagreements with the application).