W3C Web Accessibility Initiative

This page contains material related to a presentation at the Web Accessibility Best Practices Evaluation Training in Lisbon, Portugal on 5 July, 2005, as part of the WAI-TIES Project (WAI - Training, Implementation, Education, Support). It is not intended to stand-alone; rather, it is primarily provided as reference material for participants in the training.

Scope of Training and Materials: This one-day training focused on select topics that were particularly suited to the circumstances of this specific training session. It did not to cover all aspects of evaluating Web accessibility, and did not cover all Web Content Accessibility Guidelines (WCAG) 1.0 checkpoints.
No Endorsement or Recommendation of Evaluation Tools: W3C/WAI does not endorse Web accessibility evaluation tools and does not recommend one tool over another. Some tools were listed, demonstrated, and used in activities in this training. Mention of a specific tool does not imply endorsement nor recommendation. WAI does provide a comprehensive list of Evaluation, Repair, and Transformation Tools for Web Content Accessibility.

Evaluating Scripts

Shadi Abou-Zahra, W3C WAI

Last updated: 5 July 2005

Script Fallback

Beware: some tools are satisfied with empty NOSCRIPT elements

NOT Script Equivalent


Example: Script Fallback 1


<script language="JavaScript" type="text/javascript">
  document.write('<table width="' + myWidth '">');


<table id="fluid" width="100%">
<script language="JavaScript" type="text/javascript">
  document.fluid.width = myWidth;

Example: Script Fallback 2


<a href="javascript:function()">Link Text</a>


<a href="redundant.html" onClick="function()"...

Script Fallback: Approach

Obsolete Scripts

Frequently applicable to decoration scripts such as rollover effect

Example: Rollover Script


  <a href="page.html" onMouseOut="out(1)"
                       onMouseOver="over(1)" ...>Link Text</a>


  <style type="text/css">
    a:hover { ... }
  <a href="page.html" ...>Link Text</a>

Event Handlers

Special case: applets and embedded objects with own user interface

Embedded Objects

Problem: difficult to evaluate third-party plugin software

Event Handlers: Approach

Other Checkpoints