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System Usability Scale – the universal marker of product usability

System Usability Scale
System Usability Scale - the universal marker of product usability
System Usability Scale

How does it work?

Participants are asked in a survey questionnaire to indicate their level of agreement or disagreement with a number of statements in relation to systems, websites, apps, or prototypes (“Please indicate how much you agree or disagree”).

Userlytics’ SUS activity is preformatted and automatically calculated. The questions are ordered in an alternating “positively framed’ and “negatively framed” manner, with slightly different wording that is related to the usability and user experience that the participant perceived. This makes it easy for you to add a SUS task to your study, and begin gathering key data.

How do I interpret System Usability Scale scores?

Interpreting the scores usually involves the following process: The participant’s scores for each question are converted to a new number, added together and then multiplied by 2.5 to convert the original scores of 0-40 to 0-100. These are not percentages and should be used in terms of their percentile ranking.

A SUS score above a 68 is normally considered above average and anything else below average, however, it is best to use the score to compare different iterations of a design, and/or compare against a production asset, and/or compare against a competitor asset or a “best practice” asset.

System Usability Scale - the universal marker of product usability

Benefits of the System Usability Scale

Industry standard

Because the System Usability Scale has become an industry standard, with references in over 1300 articles and publications, it provides a clear “standard” benefit in terms of comparisons.

Quick and simple

The Userlytics system calculates the system usability scale (SUS) score automatically, and presents MIN, MAX AND AVERAGE results. All you need to do is fill in the blanks!

Reliable results
and analysis

When used with small sample sets, SUS is historically shown to be a very reliable measurement of product usability and likeability, making it an ideal UX testing tool.

Effective UX
testing tool

The System Usability Scale is also historically shown to be quite effective in differentiating between different study assets, and between good and bad digital product usability and likeability.

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