Bangor et al. (2008) An Empirical Evaluation of the System Usability Scale

Bangor et al. provide a nice description of System Usability Scale (SUS). Their article is based on almost 10 year’s worth of SUS data (more than 200 SUS studies). SUS is an interesting tool. It provides a reference score for participants subjective view of a products or services usability. SUS includes 10 questions that are analyzed as a whole. The scores for individual questions are not necessary meaningful yet the score of the whole SUS questionnaire reflects the participants view of the product’s usability. According to Bangor et al. SUS is not biased against certain types of user interfaces or against gender.

Bangor et al. identify six major usages for SUS:

  1. Providing a point estimate measure of usability and customer satisfaction
  2. Comparing different tasks within the same interface
  3. Comparing iterative versions of the same system
  4. Comparing competing implementations of a system
  5. Competitive assessment of comparable user interfaces
  6. Comparing different interface technologies


Bangor, Aaron , Kortum, Philip T. and Miller, James T.(2008) ‘An Empirical Evaluation of the System Usability Scale’, International Journal of Human-Computer Interaction, 24: 6, 574 — 594 LINK