SUS: The Most Used Questionnaire for Measuring Perceived Usability

The System Usability Scale (SUS) is a ten-item questionnaire administered to users for measuring the perceived ease of use of software, hardware, cell phones and websites.

SUS The Most Used Questionnaire for Measuring Perceived Usability infograph

SUS The Most Used Questionnaire for Measuring Perceived Usability infograph

It’s been around for more than a quarter century, and its wide usage has allowed us to study it extensively and write about it in this blog and in the book, A Practical Guide to the System Usability Scale.

If you are unfamiliar with the SUS, see the earlier blog for some background and fundamentals. Here are 10 things to know when using the SUS:

  1. The average SUS Score is a 68
  2. SUS measures usability & learnability
  3. Reversing the items causes more harm than good
  4. Familiarity breeds content
  5. Usability predicts customer loyalty
  6. Raw SUS scores aren’t normally distributed but the sample mean 
  7. You can use SUS on small sample sizes
  8. SUS scores were not meant to be diagnostic
  9. SUS is technology agnostic
  10. SUS might not always be the best questionnaire

 

Read the full article.