How Expertise Affects a Digital-Rights-Management-Sharing Application's Usability

Researchers performed a usability study of a digital-rights-management sharing (DRMS) application with which users protect and share digital files. Besides the standard goal of identifying usability problems, the study investigated how expertise affects objective and perceived usability, the correlations among the usability metrics, and how the usability outcomes compared with emerging norms. The researchers divided the 18 study participants into two groups of nine according to skill level. The participants performed seven DRMS tasks. The groups differed significantly in objective usability (successful task completions, errors, and completion times) and perceived usability (ratings of a variant of the System Usability Scale [SUS]). Two correlations were statistically significant (success with the SUS and success with errors); all six possible correlations were in the expected direction. On the basis of the published norms, the overall success rate was below average; the SUS's overall mean was average. The main takeaways for practitioners are two practical examples. The first involved using independently derived benchmarks to assess the perceived usability and effectiveness; the second involved testing different skill groups.