Note: This document is a draft [see change log in progress] and should not be referenced or quoted under any circumstances. This document is under development by the Education and Outreach Working Group (EOWG), and will be offered to other W3C groups and the public for review.
Web accessibility evaluation tools are software programs or online services that help determine if a Web site is accessible, and help improve Web accessibility. Read the section Conformance Evaluation to the Web Content Accessibility Guidelines 1.0 of the document Evaluating Web Sites for Accessibility to find out how to carry out a comprehensive evaluation which combines semi-automatic, manual, and user testing of accessibility features. This document explains different features of evaluation tools which can be used during a conformance evaluation and helps you to determine which types of tools and features would best meet your specific needs.
Web accessibility evaluation tools can significantly reduce the time and effort of conformance evaluations by carrying out automated checks and by assisting Web developers in evaluating checkpoints which need to be evaluated manually. Specifically, evaluation tools should perform the following functions:
Many accessibility checks remain non-automatable by current computer technology, these must be manually evaluated by experienced Web developers. The inaccuracy of evaluation tools, especially for non-automatable checkpoints, can be very misleading when Web developers lack fundamental knowledge about key accessibility requirements. Web accessibility evaluation tools can not make your Web site accessible, they can only assist you in doing so.
WAI encourages the development and evolution of Web accessibility evaluation tools, and maintains an extensive list of evaluation, repair and transformation tools. WAI does not endorse or promote any single tool or vendor.
There are several types of Web accessibility evaluation tools that help developers evaluate the conformance of Web sites to the Checkpoints of the Web Content Accessibility Guidelines 1.0, they are roughly divided into report, wizard, visual feedback, and manual evaluation tools as described below; sometimes evaluation tools can provide more than one of these operation modes.
Generally, report evaluation tools attempt to evaluate Web pages with little or no user interaction, and generate reports with the results of the accessibility checks that they carried out. Report evaluation tools are very useful in quickly determining the conformance of Web content to the checkpoints which can be automatically evaluated, or for identifying which of the remaining checkpoints need to be manually evaluated.
Wizard-based evaluation tools guide Web developers through a series of checks in a defined sequence in order to determine the conformance of the Web content to accessibility guidelines. Sometimes these tools are able to automatically execute some of the accessibility checks, leaving the remainder of the checks to be manually carried out by the Web developers. For example, an evaluation tool with a wizard interface may display the images of a Web page and their corresponding descriptions one at a time so that Web developers can evaluate how appropriate each of these descriptions are.
Visual feedback evaluation tools display the results of automated accessibility checks on the respective locations of the Web pages by inserting icons and markup into the code of the pages. By marking the location and type of errors onto the Web pages, developers can recognize the context and impact of these errors thus increase their awareness and expertise in Web accessibility.
Manual evaluation tools assist Web developers by executing checks which are related to accessibility checkpoints, or by modifying the appearence of the Web pages to help identify accessibility barriers. For example, by displaying the content in text only, by presenting the Web pages without color, or by reading the content aloud, experienced Web developers can effectively evaluate and improve the accessibility features of their Web sites.
According to your specific organization, different aspects of Web accessibility evaluation tools may be more relevant. Below are some questions which can be used to compare evaluation tools in order to determine which are most suitable for your specific needs:
Last modified: $Date: 2005/02/24 10:48:17 $ by $Author: shadi $
Last updated 1 February 2005 by Shadi Abou-Zahra. Editors: Shadi Abou-Zahra and Judy Brewer, with assistance from participants of the EOWG.
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