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 Markup
Shadi Abou-Zahra, W3C WAI
Last updated: 5 July 2005
Valid Markup
- 3.2 Create documents that validate to published formal grammars
- 11.2 Avoid deprecated features of W3C technologies
Applies to: (X)HTML, CSS, SVG, ...
Valid Markup: Approach
- Use online validation services
- Use validators built into browsers
- Use validators built into editors
Relative Units
- 3.4 Use relative rather than absolute units in markup language attribute values and style sheet property values
Applies to: (X)HTML and CSS
Relative Units: Approach
- Use browser zoom functionality
- Use different screen resolutions
- Use evaluation tools (remember CSS!)
Layout Tables
- 3.3 Use style sheets to control layout and presentation
- 5.3 Do not use tables for layout unless the table makes sense when linearized. Otherwise, if the table does not make sense, provide an alternative equivalent (which may be a linearized version)
Also very relevant to forms as we will see later
Layout Tables: Approach
- Use voice browsers or screen readers
- Use manual evaluation tools
- Use wizard evaluation tools
Data Tables
- 5.1 For data tables, identify row and column headers
- 5.2 For data tables that have two or more logical levels of row or column headers, use markup to associate data cells and header cells
- 5.5 Provide summaries for tables
- 5.6 Provide abbreviations for header labels
Data Tables: Approach
- Manually check source-code
- Evaluate summaries like alternate text
Semantic Elements
- 5.4 If a table is used for layout, do not use any structural markup for the purpose of visual formatting
- 3.7 Mark up quotations. Do not use quotation markup for formatting effects such as indentation
Caution: Q
and BLOCKQUOTE
elements are different
Tip: CODE
and PRE
elements are also often misused
Semantic Elements: Approach
- Use wizard evaluation tools
- Search for elements in the source code
Natural Language
- 4.1 Clearly identify changes in the natural language of a document's text and any text equivalents (e.g., captions)
- 4.3 Identify the primary natural language of a document
Limitation: attributes such as ALT
or TITLE
Natural Language: Approach
- Use voice browsers or screen readers
- Use word processors or spell checkers
- Also check Web server configuration