
This page contains material from a presentation at the WAI Best Practices Exchange
Training in Madrid, Spain in February 2004. It is not intended to
stand-alone; rather, it is primarily provided as reference material for
participants in the training.
Web Accessibility in Perspective
Shawn Lawton Henry, W3C WAI
Last updated: 12 October 2004
Topics
- What is Web accessibility
- Importance to people with disabilities
- Components
- WAI guidelines
- Presenting the case
- Fundamental concepts
- Interactive examples ...
Perspectives on Web Accessibility
- The ability to use Web content even when functioning under limiting
conditions
- Functional limitations ("disabilities")
- Situational limitations
- Designing so that more customers can use your Web site
effectively in more situations
Also
- Accommodating a wider range of users
- Increasing # of people who can effectively use the Web
- Accommodating users in a wider range of situations
- Increasing the situations in which the Web can be used
- Increasing usability
Videos:
Activities:
Situational limitations
- Concrete examples:
- Curb Cuts
- Closed Captions
- HTML Image Alt Text
Defining Web Accessibility
From WAI Online Overview:
- Web accessibility means access to the Web by everyone, regardless of
disability
- Web accessibility includes
- Web sites and applications ...
- Web browsers and media players ...
- Web authoring tools, and evolving Web technologies ...
WAI resource: http://www.w3.org/Talks/WAI-Intro/slide3-0.html
Components of Web Accessibility
WAI coverage of components
Anatomy of WCAG 1.0
- Guidelines
- Principles of accessible Web design
- Checkpoints
- How to satisfy the guideline
- Priorities
- Priority 1: ... must ... or impossible ...
- Priority 2: ... should ... or difficult ...
- Priority 3: ... may ... to make it easier ...
- Techniques
- Technology-specific examples and tests
Navigating WCAG 1.0 Documents
WCAG 2.0 Working Draft
- Easily understood, implemented, translated, tested
- Testable success criteria
- Benefits, definitions, examples
- Generate Checklists & Techniques for HTML, CSS, SMIL, SVG,
MathML
WAI Resource: Requirements for
WCAG 2.0
(Presenting the case, Jon Dodd)
Usability - Accessibility Synergy
- Usability: Effective, efficient, satisfying
- Accessibility: for more people in more situations
- Overlap in
- Design process & techniques
- Guidelines
Usability - Accessibility Guidelines Overlap
Activity: Consistency
- Good, nice to have for usability can be very important for
accessibility
- Mildly annoying for some can be totally unusable for others
Demo:
Fundamental Concepts
- Tomorrow ...
- Transforming gracefully
- Separation of structure and presentation
- Principles of Web accessibility
- Perceivable
- Operable
- Understandable
- Robust
Perceivable example: color coding
- WCAG
Checkpoint 2.1: ... all information conveyed with color is also
available without color ...
- WCAG
Checkpoint 2.2: ... foreground and background color combinations
provide sufficient contrast ...
Understandable example: clear links
Understandable example: identifying language
Perceivable example: units
- WCAG 1.0 Checkpoint
3.4 Use relative rather than absolute units...
- Units: relative vs. absolute
- Relative
- Text changes with browser text settings
- Common: ems (em), percent (%)
- Also unassigned!
- Absolute
- Text does not change with most browser text settings
- Common: point (pt) and pixel (px)
- Units examples: text size
Conclusion