Accessibility Evaluation of Next-generation Web Applications

Aaron Andersen and Jonathan Whiting

WebAIM: Web Accessibility in Mind

http://webaim.org/presentations/2007/csun/evaluation.html
or view this presentation JavaScript and CSS removed

Credits

WebAIM is a project of

Web Accessibility Evaluation

• Determining the accessibility levels of a given web resource.
• Necessary any time web accessibility is required or desired.

Evaluation Standards

• Evaluation is usually against one or more accessibility standards or benchmarks.
  • WCAG: Web Content Accessibility Guidelines (W3C)
  • Section 508 (United States Government)
  • Other governmental and regional regulations throughout the country and internationally.
  • General principles, collective experience, and industry consensus not formally covered by any of the above.
• Different standards often overlap and sometimes contradict each other.
• There is no single standard suitable for all realms or situations.

Evaluation Types

• Human
  • Testing performed by an actual person.
  • Quality of results depend on knowledge and experience of tester.
• Computer
  • Often very fast and efficient.
  • Can run completely automated.
  • Not everything can be computationally tested! Some things require human evaluation.
• Computer-Aided
  • Individual assisted by a computer process.

Evaluation Response Types

• Autocorrecting
  • Automatically fix any problems identified.
  • Not a realistic goal most of the time.
• Accessibility Reports
  • Generate a report of accessibility problems and their locations.
  • Good at identifying definite accessibility errors.
  • Can sometimes be difficult to locate the problem in the document source or generating tool.
• Inline Feedback
  • Insert feedback into original document.
  • Allows problems and potential problems to be evaluated in their correct context.
  • Can be difficult to identify all reported issues.

The WAVE Web Accessibility Tool

http://wave.webaim.org/

• Originated at Temple University in Philadelphia, maintained by WebAIM since 2002.
• Focuses on computer-aided accessibility evaluation.
• Provides inline feedback with unique icons and explanatory text.

WAVE3 Demo

http://wave.webaim.org/

WAVE3 Information

• Implementation Language: Java, JSP
• Evaluation Base: HTML Source
• Content Parser: Custom built, linear (SAX-style)
• Typical Monthly Usage: 40,000 pages

Limitations of WAVE 3.0

• Cannot evaluate password protected, private or intranet documents.
• Cannot evaluate documents generated using JavaScript, AJAX or DOM Scripting.
• Cannot evaluate content not in HTML or XHTML format.
• Evaluation rules cannot easily to changed or updated.
• Evaluation feedback available in English only.

Requirements for WAVE 4.0

• Must include all the major features of WAVE3.
• Must be able to evaluate password protected, private and intranet documents.
• Must be able to evaluate documents generated using JavaScript, AJAX or DOM Scripting.
• Must be able to evaluate documents in multiple formats.
• Rules and tests must be flexible and easily updated or modified.
• Must support feedback in multiple languages.

Introducing LRAE

• LRAE: Logical Rapid Accessibility Evaluation
• What is LRAE?
  • An XML-based language for defining tests (boolean assertions relating to the content of a doument) and actions (direct inline modification of the source) in response to the result of running such tests against the document.
  • Under development at WebAIM since early 2006.
  • The primary logical basis of WAVE 4.0.

LRAE Information

• Language Type: XML Application
• Processor Implementation: JavaScript, XPath
• Evaluation Base: Document Object Model

Coming Soon: WAVE4

• Currently in internal testing and quality assurance.
• First public release expected within a few months.

The WAVE4 Toolbar

• Addon toolbar for Mozilla Firefox 1.5+
• Complete WAVE functionality available.
• Tests documents based on current state at time of evaluation.
• All evaluation and processing occurs locally. Nothing is sent to WebAIM's server!

WAVE4 Toolbar Demo

LRAE Elsewhere

• Other applications and uses of the LRAE language and processor:
  1. The XUL Accessibility Tool. Created in coordination with the Mozilla Foundation. Tests accessibility of XUL-based application such as Firefox and Mozilla Thunderbird.
  2. ODAE: The Open Document Accessibility Evaluator. Prototype. Tests accessibility of Open Document Text files, such as those created by the Open Office productivity suite.
  3. Prototype tools for testing accessibility of Glade, SVG, and other file formats.

Questions?