A Simplified System Usability Scale (SUS) for Cognitively Impaired and Older Adults

Abstract

We present the 10-item Simplified System Usability Scale (SUS) for Cognitively Impaired and Older Adults, which we have used in several studies since 2016. The Simplified SUS is a revised version of the SUS, a brief, psychometrically valid, and widely used global measure of usability. To improve the ease of administration, the Simplified SUS rewords 9 of 10 SUS items and replaces the original SUS question about inconsistency with a question about confusion. The Simplified SUS retains the SUS's 10-item design, five-item agreement-based Likert scale, and alternating valence of positively worded odd items and negatively worded even items. Because of this, the Simplified SUS can be interpreted the same way as the traditional SUS. The Simplified SUS is an example of an off-the-shelf human factors method adapted for work with vulnerable populations and usable by practitioners or researchers without human factors training.