Web Accessibility Evaluation
Evaluation is a critical part of the process of developing optimally accessible Web sites - where existing resources are evaluated for potential barriers, and steps taken to address these barriers. There is a wide range of evaluation techniques, differing in terms of time, expertise and resources required to carry out the evaluation, and in the nature and quality of information the evaluation provides. An effective evaluation approach combines different methods at different times during a web resource's lifecycle.
This page provide links to resources focusing on web accessibility evaluation.
The evaluation should be based on a firm methodology to assure the quality of the results and can involve tools to carry out automated tests. Reporting templates are also essential to enable comparable reports.
Planning and Conducting Web Accessibility Evaluation
These resources provide advice and methodologies for carrying out and acting on the results of Web accessibility evaluation.
- Evaluating Websites for Accessibility (external) (W3C WAI) - a collection of resources which together give a comprehensive treatment of the process of accessibility evaluation, including evaluation methods and tools.
- Planning, Evaluation, Repair and Maintenance of Web Accessibility (external) (WebAIM) - overview of the components of an effective accessibility evaluation and repair strategy.
- Unified Web Evaluation Methodology (UWEM) (external) (WAB Cluster) - a formal methodology for evaluating Web site accessibility, the output of the European-funded Web Accessibility Benchmarking Cluster, three related projects on Web accessibility evaluation.
There are a range of methodologies to evaluate the accessibility of a website. A list of methodologies used around the world can be found on the Website Accessibility Evaluation Methodologies (external) wiki.
Both user testing and automated tools can be used to evaluate the accessibility of a web site. An overview of the process of testing a website from beginning to end is the WAI Evaluation Suite (external). To enable conformance claims to existing standards, a predefined protocol is needed. A complete methodology for the evaluation of website conformance for WCAG 1.0 conformance is provided by UWEM (external).
The WCAG 2.0 Evaluation Methodology Task Force (Eval TF) (external) will prepare a methodology to evaluate according to WCAG 2.0.
While there is no substitute for carefully planned testing by real users of accessibility and AT, a level of automated and manual testing can and should should be carried out as part of all project and product development.
There are a many freely available tools, especially for web validation and accessibility testing. In addition open source AT such as the NVDA screen reader (external) allow basic eAccess 'smoke' tests (external) to be carried out by developers.
To evaluate the accessibility of a website, you can deploy automatic tools or carry out user testing (or a combination of both).
A range of tools exist to support the task of Web accessibility evaluation. The number, quality, and availability of tools that can support web accessibility evaluation is constantly changing, however, so this list is not definitive; the presence of a tool on this list does not indicate eAccess+ endorsement for that tool. All of the tools on the list below provide a free, online accessibility checker. W3C WAI provides a Complete List of Web Accessibility Evaluation Tools (external); however at the time of writing (June 2012), this is known to require updating.
General automated accessibility evaluation tools:
- A-Checker (external), provided by ATRC, University Of Toronto.
- Cynthia Says (external), provided by HiSoftware.
- eGovMon eAccessibility checker (external), provided by the Norwegian eGovMon project. eGovMon checker tools can check web pages, web sites and PDF documents. They are all open source.
- Functional Accessibility Evaluator (external), provided by University of Illinois.
- Imergo (external), provided by the Web Compliance Center of the Fraunhofer Institute for Applied Information Technology (FIT). The Imergo tool was developed to target big commercial Web applications to support the industry in implementing Web Compliance Engineering methods. Web Compliance is not reduced to accessibility. It includes an online restricted demo.
- Sort Site (external), provided by PowerMapper.
- TAW (external). provided by CTIC.
- The WAVE (external), free web accessibility evaluation tool provided by WebAIM. It is used to aid humans in the web accessibility evaluation process. Rather than providing a technical report, WAVE shows the original web page with embedded icons and indicators that reveal the accessibility of that page.
- WebAccessibilityToolbar, provided by Vision Australia and The Paciello Group. This provides a suite of accessibility checking tools into a browser toolbar available for Internet Explorer.
- Web Developer Toolbar (external), provided by Chris Pederick. This combines a suite of accessibility checking tools with other general web markup evaluation tools into a browser toolbar available for Firefox and Chrome.
Tools for specific evaluation activities:
- Colour Contrast Analyser (external) (The Paciello Group) - tool for reporting on contrast between colours.
- Colour Contrast Checker (external) (Snook.ca) - tool for reporting on contrast between colours.
- Vischeck colour deficit simulator (external) - tool to show how a web page might appear to someone with colour deficit.
To report the results from a web site evaluation, a reporting methodology may help. A consistent and comprehensive evaluation report format can help ensure effective evaluations as well as accurate comparisons of accessibility levels over time and between different Web sites.
- W3C WAI recommended format for evaluation (external) for communicating results of the evaluation of Web site accessibility according to the Web Content Accessibility Guidelines (WCAG) 1.0.
More on web accessibility: