Extração de métricas de usabilidade a partir de protótipos de fidelidade mista

Abstract

Nowadays, a considerable part of usability evaluations carried out during the software development lifecycle is conducted at later stages. Some of these assessments depend on the creation of fully functional prototypes, so they can be applied, and they re commonly performed after the development and deployment of software. This factor contributes significantly to the increase in cost of production. In this sense, from the research of prototyping, usability engineering and the conduction of a systematic review, this work presents an approach that allows the usability evaluation anticipation, through the use of mixed-fidelity prototypes created via the use of a computational tool. This tool assists in the creation and simulation of prototype interfaces, and enables collecting the following metrics of usability, for further analysis: task success, giving up on tasks, time on task, effort, screen balance, screen symmetry, screen balance, sequencing, order and complexity and system usability scale. In addition to the metrics that are collected by the tool automatically, other metrics are proposed to be collected from the observation of users using the prototypes created: partial success of the task, number of errors, help and documentation, time help, anger or frustration. The analysis of the obtained metrics point to areas of the system with potential usability problems. Moreover, the execution of new tests using the interfaces refined with the approach aid allow us to quantify the improvements resulting of the layout changes. In addition to the approach, the work presents its use in an experiment conducted with users. This experiment showed that, although not ali the metrics that can be collected from prototypes contribute to the refinement of interfaces, it was still possible to reduce the number of usability problems by just analyzing the results of the metrics.