The Factor Structure of the System Usability Scale

Abstract

Abstract. Since its introduction in 1986, the 10-item System Usability Scale (SUS) has been assumed to be unidimensional. Factor analysis of two independent SUS data sets reveals that the SUS actually has two factors -Usable (8 items) and Learnable (2 items -specifically, Items 4 and 10). These new scales have reasonable reliability (coefficient alpha of .91 and .70, respectively). They correlate highly with the overall SUS (r = .985 and .784, respectively) and correlate significantly with one another (r = .664), but at a low enough level to use as separate scales. A sensitivity analysis using data from 19 tests had a significant Test by Scale interaction, providing additional evidence of the differential utility of the new scales. Practitioners can continue to use the current SUS as is, but, at no extra cost, can also take advantage of these new scales to extract additional information from their SUS data. The data support the use of "awkward" rather than "cumbersome" in Item 8.

In the Eye of the Beholder: Promoting Learner-Centric Design to Develop Mobile Games for Learning

“…To measure learners' perception of the game simulation, we assessed system usability, learnability, game-play experience and attitude towards the use of educational games in general. In order to assess system usability and learnability, we chose the SUS because it is an accepted measure that makes results easily comparable [13]. We used the standard Overall SUS score, instead of the 8-item Usability scale, because the Overall SUS allows estimating perceived Learnability along with perceived Usability [13].…”

“…In order to assess system usability and learnability, we chose the SUS because it is an accepted measure that makes results easily comparable [13]. We used the standard Overall SUS score, instead of the 8-item Usability scale, because the Overall SUS allows estimating perceived Learnability along with perceived Usability [13]. The items had to be rated on a 5-point Likert-scale ranging from 1=strongly disagree to 5=strongly agree.…”

Feasibility of a New Cuffless Device for Ambulatory Blood Pressure Measurement in Patients With Hypertension: Mixed Methods Study (Preprint)

“…Patient experience and performance were evaluated by a widely used and reliable questionnaire to determine the feasibility of different products, and all interviews followed an interview guide derived from a well-known interview framework. [28,48] Possible weakness of this study was the small study sample, which may not guarantee complete saturation in all qualitative aspects. The relative short follow-up may also have led to an incomplete user experience.…”

The Effect of Perceived Expected Satisfaction with Electronic Health Records Availability on Expected Satisfaction with Electronic Health Records Portability in a Multi-Stakeholder Environment

“…The System Usability Scale (SUS) has received positive recognition and been applied by a number of researchers (Brooke, 1996;Lewis & Sauro, 2009). Another such method is the Software Usability Measurement Inventory, which requires "Agree", "Don't Know", or "Disagree" input from users on 50 subjective statements.…”