Towards a score function for WCAG 2.0 benchmarking

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Read the publication: Towards a score function for WCAG 2.0 benchmarking .

Title: Towards a score function for WCAG 2.0 benchmarking.
Author(s): Annika Nietzio, Mandana Eibegger, Morten Goodwin, and Mikael Snaprud.
Published date: December 2011.
Published at: W3C, Website Accessibility Metrics 2011


Monitoring of web accessibility through regular benchmarks raises awareness and thus incites improvements of web sites. The eGovernment Monitoring (eGovMon) project [1] has collaborated with a group of Norwegian municipalities during more than two years, achieving encouraging results by a combination of evaluations and consultancy.

Initially, eGovMon used benchmarking tools based on the Unified Web Evaluation Methodology 1.2 (UWEM) [2], which describes conformance evaluations and large scale benchmarking for WCAG 1.0. However since WCAG 1.0 was superseded by WCAG 2.0, the eGovMon approach (including the implemented tests) had to be updated to accommodate the new guidelines.

This paper describes the requirements and challenges identified during the update of the metrics and reporting functions for WCAG 2.0 benchmarking. The core part of the reporting is the score function, which summarises the accessibility status of a web page or site into a single number.

First we look at the requirement perspective: What are the desirable properties of an accessibility score function? Then we take a WCAG 2.0 specific view with special consideration to the new properties of WCAG 2.0 (as compared to WCAG 1.0). Beyond that, the final section of the paper presents some ideas for developing a unified WCAG 2.0 score function, which would allow the comparison of WCAG 2.0 evaluations carried out by different tools.

Ideally not only results from different tools should be comparable; it is also desirable to obtain more insights in the comparability of expert evaluations and automated tests. However this topic is beyond the scope of this paper.

The author of this document is:
Morten Goodwin
E-mail address is:
morten.goodwin [at]
Phone is:
+47 95 24 86 79