Introduction to Volume 15, Issue 3

Our May 2020 issue features an essay from Bernard Rummel, “About Time: A Practitioner’s Guide to Task Completion Time Analysis.” This essay brings together lines of research that he has published in the Journal of Usability Studies, formatted to help practitioners understand how to get more out of time-on-task data collected in usability studies. 

In addition to the essay, this issue includes three research papers, one on a mobile application for administering the System Usability Scale and two on health-related research.

The first article is “SUSapp: A Free Mobile Application That Makes the System Usability Scale (SUS) Easier to Administer,” by Jeffrey Xiong, Claudia Ziegler Acemyan, and Philip Kortum. The System Usability Scale is a very popular measure of perceived usability. In its standard form, however, usability practitioners sometimes do not correctly compute its score. The authors describe the development and assessment of a mobile app designed to help practitioners and researchers easily collect data, compute SUS scores, and export the data.

The second article is “User Evaluation of Low-Cost, Non-Invasive Methods for Heart-Rate Measurement,” by Eirini Mathe and Evaggelos Spyrou. They investigated three methods for obtaining low cost and non-invasive heart rate measurement: using a camera connected to a personal computer, using a mobile phone app, and using a smart bracelet. The results obtained from two different UX questionnaires (the SUS and a custom questionnaire) were inconsistent, with the SUS supporting the camera-based approach and the custom questionnaire supporting the mobile app. Based on participant complaints about a specific aspect of the experience of using the mobile app to which the custom questionnaire was apparently not sensitive, they concluded that the best overall method was the computer-connected camera.

In the third article, “Testing Usability of the Eye Health Evidence Gap Map,” Bhavisha Virendrakumar, Emma Swain, Rachel Murphy, and colleagues describe usability testing of evidence gap maps (EGM). These are tools for the visual presentation of evidence on the effects of interventions, in this study applied to interventions that address different conditions causing visual impairment. Difficulties encountered by participants helped to identify changes that could make EGMs more effective.