Measuring Perceived Usability: The CSUQ, SUS, and UMUX
ABSTRACT The primary purpose of this research was to investigate the relationship between two widely used questionnaires designed to measure perceived usability: the Computer System Usability Questionnaire (CSUQ) and the System Usability Scale (SUS) The correlation between concurrently collected CSUQ and SUS scores was 0.76 (over 50% shared variance) After converting CSUQ scores to a 0 100 point scale (to match the range of the SUS scores) there was a small but statistically significant difference between CSUQ and SUS means. Although this difference (just under 2 scale points out of a possible 100) was statistically significant, it did not appear to be practically significant. Although usability practitioners should be cautious pending additional independent replication, it appears that CSUQ scores, after conversion to a 0 100 point scale, can be interpreted with the Sauro Lewis curved grading scale. As a secondary research goal, investigation of variations of the Usability Metric for User Experience (UMUX) replicated previous findings that the regression adjusted version of the UMUX LITE (UMUX LITEr) had the closest correspondence with concurrently collected SUS scores. Thus, even though these three standardized questionnaires were independently developed and have different item content and formats, they largely appear to be measuring the same thing, presumably, perceived usability.
Int. J. Hum. Comput. Interact.