Accessibility and the Web: What You Don't Know Can Hurt
What is accessibility
- Describes the degree to which a system is usable by as many people as possible without modification.
- Web accessibility specifically focuses on people with disabilities and their use of assistive devices such as screen-reading web browsers or other devices.
- Not Usability.
The Law
- ADA (Americans with Disabilities Act)
- Section 504
- Applies to employers and organizations that receive federal financial assistance
- Office of Civil Rights
- Prevents intentional or unintentional discrimination
- Courts say post-hoc, or after the fact, accommodations are not tolerated
- Section 508 -
Provides the direction of Section 504, and the how to.
- Bars the Federal government from procuring Electronic and Information Technology goods and services that are not fully accessible to those with disabilities
- Sets standards for internet
- Businesses must comply with Section 508 when supplying Electronic and Information Technology goods
- State governments can be held accountable for compliance
- SRRPUB11 - State Web Site Guidelines on Web Accessibility & Usability
The Law at Work
- NFB(National Federation of the Blind) v. Target February 7, 2006
- Alt-text
- Inaccessible image maps
- Requires the use of a mouse to complete a transaction
Besides the Law
- Ethical
- 20%, 1 in 5 persons have some sort of disability
- Related implications for others
- Business
- Emerging Technologies - cell phones, PDA's
- Compatibility - platforms, operating systems, browsers
- Load faster - cached
- Smaller page sizes
Making our sites accessible
- Understand the types of disabilities
- Understand how assistive technologies work
- Understand Section 508 guidelines and priorities
- Code to standards (W3C)
- Testing (W3C)
- Know where to get answers
Types of disabilities
- Visual
- Blindness
- Low vision
- Color blindness
- Hearing
- Motor
- Inability to use mouse
- Slow response time
- Limited fine motor control
- Cognitive
- Learning disabilities
- Distractibility
Assistive Technologies
- Visual
- Images
- Visual Layout
- Data tables
- Hearing
- Movies
- Sound
- Captioning
- MAGPie (Media Access Generator) - allows the captioning of Web audio and video content
- Quick time
- Real Player
- Window Media Player
- Motor
- Unable to control mouse or keyboard
- Voice recognition
- Head wand
- Mouth Stick
Generally Guidelines - W3C
- Priorities
- Priority 1
- Must satisfy this checkpoint
- Priority 2
- Should satisfy this checkpoint
- Priority 3
- May address this checkpoint
- Conformance Levels
- Level A - all Priority 1 checkpoints satisfied
- Level Double A - all Priority 1 and 2 checkpoints satisfied
- Level Triple A- all Priority 1, 2, and 3 checkpoints satisfied
Guidelines for Priority 1 and 2
- Guideline 1 - Alternative equivalent to auditory and visual content
- Images, image map regions, animations, frames,
- Audio
- Text equivalent - captioning (magpie)
- Guideline 2 - Don't rely on color alone
- Can the information be conveyed without color
- Contrast, can you view it on a black and white screen
- Guideline 3 - Use markup and style sheets (css) properly
- Separate content, presentation, and structure
- Content - copy, images, sound, etc.
- Structure (html) - specifies document structure (p, blockquote)
- Presentation (css) - rendering on screen or print (font, center)
- Guideline 4 - natural language usage
- Mark up natural language changes in a document
- Guideline 5 - create tables that transform gracefully
- Truly tabular information
- Include row and column headers
- Guideline 6 - newer technologies
- Work with older browsers
- Work if feature is turned off - scripts, applets
- Readable without style sheets
- Guideline 7 - user control of time-sensitive content
- Moving, blinking, scrolling, or auto-updating objects may be paused or stopped
- Flickering or flashing - photosensitive epilepsy
- Blink and Marquee elements
- Auto refresh - user controlled
- Redirects - server side
- Guideline 8
- embedded interfaces must follow accessible principles
- Flash - compatible with assistive technologies
- Guideline 9
- design for device-independence
- Device - mouse, keyboard, voice, head wand, etc.
- Provide client-side image maps
- Provide text equivalents for image map images and links
- Create logical tab orders - links, forms, objects, etc.
- Guideline 10 - use interim solutions, user agents
- User agent - software to access Web content
- Firefox, Explorer, Safari, etc.
- Do not cause pop-ups or other windows to spawn without user input
- Ensure form labels are positioned properly
- Include place-holding characters in edit boxes and text areas
- Include skip links navigation
- Guideline 11 - use W3C technologies and guidelines
- Page can not be made accessible
- Accessible alterative page
- Equivalent information
- Up to date
- Guide 12 - context and orientation information
- Frames
- Each frame must include title
- Guide 13 - clear navigation mechanisms
- Clearly identify target of links
- Include metadata
- Include a site map
- Create consistent navigation
- Guide 14 - ensure documents are clear and simple
- Use clearest simplest language
-
Code to standards
- Formal standards and other technical specifications that define aspects of the WWW
- Consistency
- Accessibility
- W3C - recommendations or specifications
Testing = Validators
- W3C
- Firefox - Web developer toolbar