Investigating and Measuring Usability in Wearable Systems: A Structured Methodology and Related Protocol

Abstract

Wearable systems are pervading our lives in several applications: from fitness to sport, from health monitoring to rehabilitation, up to prosthetics and empowering human functions through exoskeletons. If the technological requirements are mainly quantitative and easy to measure, their usability, acceptance, and user experience are generally poorly studied. There is a lack of a structured methodological approach to develop a comprehensive protocol. This paper aimed at providing these methodological bases and at defining some of the related tools. The first action was to clearly define the objectives of the study: (a) to identify design inconsistencies and usability problems or errors; (b) to validate the use of wearable systems under controlled test conditions with representative users; and (c) to establish a baseline in terms of user performance and user satisfaction levels. A five-step approach should be adopted: (1) define the target users; (2) conduct a task analysis for identifying the context, the parameters to be measured, and the methodology to collect data; (3) prepare a protocol and the investigation tools; (4) execute the usability experiments; and (5) analyze and report the data. This segmentation of the complex task of usability measurement into single steps can help in elaborating a proper protocol where users, usability factors and parameters, and their recording tools (questionnaires or measurement methods) are correctly identified and prepared for the experimental activity. The application of this methodology can support researchers, developers, and users in improving the deployment of these devices in our lives and the exploitation of these systems for increasing our quality of life.