Procedures of User-Centered Usability Assessment for Digital Solutions: Scoping Review of Reviews Reporting on Digital Solutions Relevant for Older Adults

BACKGROUND: The assessment of usability is a complex process that involves several steps and procedures. It is important to standardize the evaluation and reporting of usability procedures across studies to guide researchers, facilitate comparisons across studies, and promote high-quality usability studies. The first step to standardizing is to have an overview of how usability study procedures are reported across the literature. OBJECTIVE: This scoping review of reviews aims to synthesize the procedures reported for the different steps of the process of conducting a user-centered usability assessment of digital solutions relevant for older adults and to identify potential gaps in the present reporting of procedures. The secondary aim is to identify any principles or frameworks guiding this assessment in view of a standardized approach. METHODS: This is a scoping review of reviews. A 5-stage scoping review methodology was used to identify and describe relevant literature published between 2009 and 2020 as follows: identify the research question, identify relevant studies, select studies for review, chart data from selected literature, and summarize and report results. The research was conducted on 5 electronic databases: PubMed, ACM Digital Library, IEEE, Scopus, and Web of Science. Reviews that met the inclusion criteria (reporting on user-centered usability evaluation procedures for any digital solution that could be relevant for older adults and were published in English) were identified, and data were extracted for further analysis regarding study evaluators, study participants, methods and techniques, tasks, and test environment. RESULTS: A total of 3958 articles were identified. After a detailed screening, 20 reviews matched the eligibility criteria. The characteristics of the study evaluators and participants and task procedures were only briefly and differently reported. The methods and techniques used for the assessment of usability are the topics that were most commonly and comprehensively reported in the reviews, whereas the test environment was seldom and poorly characterized. CONCLUSIONS: A lack of a detailed description of several steps of the process of assessing usability and no evidence on good practices of performing it suggests that there is a need for a consensus framework on the assessment of user-centered usability evaluation. Such a consensus would inform researchers and allow standardization of procedures, which are likely to result in improved study quality and reporting, increased sensitivity of the usability assessment, and improved comparability across studies and digital solutions. Our findings also highlight the need to investigate whether different ways of assessing usability are more sensitive than others. These findings need to be considered in light of review limitations.