Advanced – Usability & Accessibility
Usability Metric – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
A measure used to assess the usability of a product, such as task success rate, time on task, or system usability scale (SUS) score.
In simple words
Numeric measures of how easy or effective a product is to use.
Exam tip
SUS, NPS, task completion rate, and time on task are the most common.
Related terms
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