- From: Charles McCathieNevile <charles@w3.org>
- Date: Tue, 16 Feb 1999 15:36:41 -0500 (EST)
- To: WAI AU Guidelines <w3c-wai-au@w3.org>
It seems to me that although the guidelines refer to several other documents which treat particular subjects more fully (for example the Web Content Accessibility Guidelines, Notes on SMIL and CSS, and various documents dealing with the accesibility of software applications) we should summarise the most important points of those documents, as well as referring to them as 'authorative sources'. This opens a Pandora's box of opportunities, but one into which I feel we should look. As points for discussion, rather than a specific proposal, I think we should make mention of the following principles: In section 2: Content produced must be device independent, or should have accompanying information (eg alternative and/or descriptive text) which can be used to ensure the information or function provided by that content is accessible. For example, where a Java applet is used to provide a navigation system, an alternative system which relies on ordinary HTML must also be offered. This could be done in the content of the OBJECT or APPLET element. Content produced must seperate, or allow the seperation of, presentation from structure. For example, where headings are indicated with a certain colour and font-style, it must be done by applying style to the appropriate level of Heading element (H1, H2, etc in HTML) rather than styling 'ordinary' text (content of a P in HTML) Content produced should have simple and consistent orientation and navigation. For example, navigation bars should use icons and ALT text consistently (see appropriate guidelines/checkpoints). Features which disorient users (such as the unexpected opening of new windows) should be avoided. In Section 4: Access to functions provided by the tool should be device independent. In many instances this can be achieved by providing keyboard access to every function, according to operating system conventions, since in nearly all operating systems any device can control the keyboard commands. Although this may in principle be true of a mouse, the use of a mouse is exceptionally difficult for many users, as it requires much more complex feedback than keboard-based functions. The representation of content must be configurable. For example, font sizes and colours used in editing the content must be configurable independently of the intended representation of them by a user agent. Representation of the content being produced must be accessible through an interoperable accessiblity interface. Complex elements (such as tables), or those which can only be rendered in certain media (such as graphics) may not be otherwise accessible to users who are relying on a representation other than a common-sized colour monitor. For example, the position within a table, and the relationship of the 'current' cell to other cells may not be readily apparent via a speech interface, and requires a further exposure of the document structure. As dynamic content becomes more wdiespread, this need is likely to increase significantly. I think that this effectively covers the issues, although the reader must, of course, be referred to the various full treatments which are included as references in the document. I feel that something along these lines justifies the volume it adds to the document. What do others think? Charles --Charles McCathieNevile mailto:charles@w3.org phone: +1 617 258 0992 http://purl.oclc.org/net/charles W3C Web Accessibility Initiative http://www.w3.org/WAI MIT/LCS - 545 Technology sq., Cambridge MA, 02139, USA
Received on Tuesday, 16 February 1999 15:36:45 UTC