2.01 Common issues: Text equivalents

Isn't that just alt tags with a different name?

• They clutter my pages with ugly tooltips and unnecessarily bloat the HTML.
• Why is it considered a hindrance to accessibility?
• My intended audience does not include the blind so why should I bother?
• The blind cannot see the images anyway so what use is a short description?

Outcome

• To raise awareness how the visually impaired view a website.
• To be able to recognise the common faults when using alternative text descriptions.
• To be able to write effective alternative descriptions,

Details:

1. Overview.
2. Images in context.
3. Tooltips & logos.
4. Decorative images, bullets & horizontal rules.
5. Text in images.
6. Text in navigation images.
7. Navigational icons.
8. Image-map navigation.
9. Graphs & diagrams.
10. Multimedia and Flash.
11. Summary.

Who does it affect?

• Users of low-bandwidth devices such as PDA's or mobile phones.
• Users reliant on assistive technologies like screen readers or Braille technologies.
• Users with hearing impairments.
• Those with motor-neurone deficiencies.
• Search engines looking for media.
• Text-only browsers.
• Your search engine ranking.

WAI guidelines

• 1.1 Provide a text equivalent for every non-text element (e.g., via "alt", "longdesc", or in element content). This includes: images, graphical representations of text (including symbols), image map regions, animations (e.g., animated GIFs), applets and programmatic objects, ASCII art, frames, scripts, images used as list bullets, spacers, graphical buttons, sounds (played with or without user interaction), stand-alone audio files, audio tracks of video, and video. [NGfL requirement]
• 1.2 Provide redundant text links for each active region of a server-side image map.
• 1.3 Until user agents can automatically read aloud the text equivalent of a visual track, provide an auditory description of the important information of the visual track of a multimedia presentation. [NGfL requirement]
• 1.4 For any time-based multimedia presentation (e.g., a movie or animation), synchronize equivalent alternatives (e.g., captions or auditory descriptions of the visual track) with the presentation. [NGfL requirement]
• 1.5 Provide redundant text links for each active region of a client-side image map.
• 11.4 If, after best efforts, you cannot create an accessible page, provide a link to an alternative page that uses W3C technologies, is accessible, has equivalent information (or functionality), and is updated as often as the inaccessible (original) page. [NGfL requirement]

Further information:

• MCU: How to make non-text elements accessible.
• Juicy Studio: Alternatives to auditory and visual content.
• WebAim: Creating Accessible Images.
• Jim Thatcher: Alternative Content for Graphics.
• W3C: Use the alt attribute.
• Jukka Korpela: Guidelines on alt texts in img elements.
• GAWDS: Writing good ALT text.
• Dive Into Accessibility: Providing text equivalents for images.
• A.J.Flavell: Use of ALT texts in IMGs.
• NCAM: Media Access Generator (MAGpie) for creating captions and audio descriptions for rich media.
• Malarkey: Accessible alternatives.
• Macromedia: Accessibility and Macromedia Flash MX 2004