- From: Ian Jacobs <ij@w3.org>
- Date: Thu, 16 Dec 1999 21:20:56 -0500
- To: Jason White <jasonw@ariel.ucs.unimelb.edu.au>
- CC: Web Content Accessibility Guidelines <w3c-wai-gl@w3.org>
Jason White wrote: > > I disagree completely with the approach which Robert Neff is advocating in > this discussion. The priorities are to be determined on the basis of > impact (as Eric calls it). One moment, please. I think this is an important discussion. 1) The WCAG WG clearly established a scheme in which priority levels are based on impact. 2) The ATAG WG adopted that scheme except that some participants in the WG felt that other schemes would also be useful. If I recall (and I may not, so excuse me), one scheme might have been: "Priority 1 means that it must be satisfied to meet the needs of expert users; Priority 2 must be satisfied to meet the needs of average users; Priority 3 for novice users" 3) Robert Neff has suggested that implementation difficulty should also be considered in deciding a checkpoint's priority. I think it's very interesting to consider that other models than "impact on the user" are conceivable. In fact, we should embrace them to make our work easier and to keep our process transparent as much as possible. Consider the following ratings for checkpoint 1.1 of WCAG 1.0: "Provide a text equivalent for every non-text element." Priority 1: Means: Vital to removing barriers to accessibility Difficulty 3: Means: It's easy to provide text equivalents that aren't synchronized with other content Standard 1: Means: Browsers and assistive technologies support text today and support consistently. Summarizing: - "Priority" refers to impact on users - "Difficulty" refers to effort required by authors or developers - "Standard" refers to current software support status Comments: 1) There's no need to have a 1-2-3 scale for each rating model 2) There could be other rating models than these. For instance, the "content vs. user interface" division is useful in both ATAG and UAAG. I think we all use more than one rating model for choosing the priority of a checkpoint, though often the rating process goes on silently because it diverges from the "impact" model we currently use. By exposing the models we silently employ, I'll bet: 1) We can avoid a number of discussions that in fact stem from the application of different and unspoken rating criteria; 2) We can provide more useful information to readers (though not necessarily all in one document); 3) We can systematize the way we think of checkpoints and add them to the guidelines. I do not mean to complicate the actual priority definitions; I think we should stick with "Priority" to mean "impact on the user". However, it's not only worth considering alternative models, I think we would benefit greatly from a fresh approach. - Ian -- Ian Jacobs (jacobs@w3.org) http://www.w3.org/People/Jacobs Tel/Fax: +1 212 684-1814 Cell: +1 917 450-8783
Received on Thursday, 16 December 1999 21:21:09 UTC