Perhaps the central theme of accessible design is the need for text alternatives to graphic elements. In this chapter, we illustrate the importance of this provision as we examine how museums represent their enormous collections of physical artifacts and information. We address a number of accessibility issues, paying particular attention to the treatment of ALT text and other equivalent text alternatives, as we explore online collections.
1. Provide equivalent alternatives to auditory and visual content.
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. [Priority 1]
1.2. Provide redundant text links for each active region of a server-side image map. [Priority 3]
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. [Priority 1]
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. [Priority 1]
7.4. Until user agents provide the ability to stop the refresh, do not create periodically auto-refreshing pages. [Priority 2]
9. Design for device-independence.
9.1. Provide client-side image maps instead of server-side image maps except where the regions cannot be defined with an available geometric shape. [Priority 1]
10.1. Until user agents allow users to turn off spawned windows, do not cause pop-ups or other windows to appear and do not change the current window without informing the user. [Priority 2]
10.2. Until user agents support explicit associations between labels and form controls, for all form controls with implicitly associated labels, ensure that the label is properly positioned. [Priority 2]
10.3. Until user agents (including assistive technologies) render side-by-side text correctly, provide a linear text alternative (on the current page or some other) for all tables that lay out text in parallel, word-wrapped columns. [Priority 3 ]
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. [Priority 1]
12.1. Title each frame to facilitate frame identification and navigation. [Priority 1]
12.2. Describe the purpose of frames and how frames relate to each other if it is not obvious by frame titles alone. [Priority 2]
12.4. Associate labels explicitly with their controls. [Priority 2]
13.4. Use navigation mechanisms in a consistent manner. [Priority 2]
13.6. Group related links, identify the group (for user agents), and, until user agents do so, provide a way to bypass the group. [Priority 3]
(a) A text equivalent for every non-text element shall be provided (e.g., via "alt", "longdesc", or in element content).
(e) Redundant text links shall be provided for each active region of a server-side image map.
(f) Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape.
(i) Frames shall be titled with text that facilitates frame identification and navigation.
(n) When electronic forms are designed to be completed online, the form shall allow people using assistive technology to access the information, field elements, and functionality required for completion and submission of the form, including all directions and cues.
(o) A method shall be provided that permits users to skip repetitive navigation links.
