Accessibility Metric

A quantitative measure used to assess and compare the accessibility quality of web pages or websites. Accessibility metrics typically calculate a score (often 0-100%) based on the number and severity of WCAG violations found, weighted by conformance level (Level A weighted higher than AAA). While metrics provide useful summary information for comparing sites or tracking improvement over time, research has shown they can be misleading — particularly when comparing the same page from different disability perspectives. Normalisation processes can diminish real differences between user groups: a page might score similarly for generic and hearing-impaired evaluations despite having 12 times more actual failures in the generic case. Effective accessibility metrics should account for the perspective of specific user groups rather than treating all violations as universally equivalent.