- From: Al Gilman <Alfred.S.Gilman@ieee.org>
- Date: Mon, 4 Feb 2008 14:23:20 -0500
- To: wai-xtech@w3.org
On 1 Feb 2008, at 9:28 AM, Laura Carlson wrote: > > Thank you very much, for moving the ALT issue forward on the the > Protocols and Formats WG's agenda. ** summary I think that a better way to frame the argument is something like: <reasoning> 1. By the principles, HTML5 wants to support accessibility 2. By their charters, WAI groups (here WCAG) are the go-to experts in matters of accessibility 3. WCAG requires @alt (WCAG1) or the function that in HTML4 is provided by @alt (WCAG2) [editorial note -- add links] 4. By the principles, if it 'tain't broke, don't fix it. 5. Conclusion: barring the introduction of three fresh good reasons for a change, the failure of the HTML5 draft to make @alt on <img> an across-the-board requirement (even if sometimes it has the value of "") is a bug. Or do you have reasons? </reasoning> Does this work for you? ** long form, inline responses On 1 Feb 2008, at 9:28 AM, Laura Carlson wrote: > > Thank you very much, for moving the ALT issue forward on the the > Protocols and Formats WG's agenda. Sorry the response to your original query has been a long time coming. > On the process point, PFWG may want to consider that WAI is the W3C > authority on accessibility; not HTML5. Definitely, WAI are the experts on accessibility and HTML the experts on HTML. For the division of labor between format and best practice in promoting accessible HTML, the experts need to work together and listen to one another. Do you consider that the most recent draft response makes this point adequately? <quote cite="http://lists.w3.org/Archives/Public/wai-xtech/2007Nov/0070.html"> WCAG WG is chartered to set Accessibility guidelines and HTML WG is not; so HTML5 should be careful to create features that support WCAG and describe their use in ways that conform to WCAG. </quote> > HTML5 must support WCAG. That statement sounds obvious enough. On the other hand there are many ways HTML can 'support' WCAG, and the devil is in the details. In this conversation we should look more closely at what the kinds of 'support' that may come from HTML5, and how W3C decides what support it *will* provide. W3C Process doesn't really set out how much weight must be given to existing Recommendations by new Recommendations. Clearly the desire is to make them 100% cooperative, but the mapping is not trivial and the performance to date is mixed. Since by the Principles propounded by the HTML Working Group they *want* to support accessibility, let's build on that and find an answer to *how* HTML5 supports accessibility that works. > Under both WCAG1 and WCAG2, text alternatives > for all <img> elements is a "priority 1" (respectively, "level 1"). To > support accessibility, HTML5 must require what is necessary to > implement WCAG. Not necessarily. One could also consider as support a format that defines the necessary structures, but does not enforce their use. The failure of the format to duplicate the WCAG rule does not in and of itself contradict the rule. [separation added.] > According to WCAG alt is required. In terms of WCAG1 that is true. In terms of WCAG2 a text alternative is required. The format specifics have been removed from the success criterion. The difference matters. In looking toward HTML5 which may take longer to finalize that even WCAG2, it is important to look at the trend, the nature of the differences between WCAG1 and WCAG2. > Omitting the alt attribute for critical content contradicts WCAG and > ATAG. agreed > If HTML5 doesn't consider this important enough to require, it > might as well be saying WCAG is not really required either. I don't follow this escalation at all. The HTML5 draft is clear that, at a moral level, the critical content *should* have its text alternate, in the @alt attribute. When they say "none may be available, or obvious," the narrative discussion suggests a division of labor where the photo-sharing site provides the markup and the public provides the image content. It doesn't matter much whether it's a format rule or a WCAG rule that has been violated; what is going to affect public behavior is things like: Will the photo sharing portal refuse to share the pictures that don't have text alternatives? I doubt it. Will the browsers of the grandparents refuse to display the baby's picture because there is no text alternative? I doubt it. If not, what will happen and when? The question in terms of deployment is "what is going to happen to you or your content if you violate this rule?" It's not a question of "is it a language rule?" or "is it an accessibility rule?" but "what is going to happen?" Josh and I would seem to be agreed that "refuse to process such a page in the browser" is justified for a critical-content image that is lacking @alt. The problem with the immediate section about <q>A key part of the content that doesn't have an obvious textual alternative</q> .. is the casual, colloquial way it is written. It neither meets the need of software developers for a crisp rule they can program to, and at the same time it irritates access advocates by allowing the inference that it disagrees with the accessibility Recommendations. > In addition the HTMLWG's own Design Principles state: > "Design features to be accessible to users with disabilities. Access > by everyone regardless of ability is essential. This does not mean > that features should be omitted entirely if not all users can make > full use of them, but alternate mechanisms should be provided. The > image in an img may not be visible to blind users, but that is a > reason to provide alternate text, not to leave out images." [1] > > [1] http://dev.w3.org/html5/html-design-principles/ > Overview.html#accessibility In terms of the Principles, one shouldn't overlook the "evolution not revolution" idea. @alt as a required attribute is the status quo. HTML WG has a stated preference to let sleeping dogs lie unless there is a distinct good reason to change things. So there are two stated preferences of HTML WG that would support keeping html5:img.alt as a required attribute. But that's not an accessibility requirement. The accessibility requirement is, as said in WCAG2 that there be a text alternative. HTML5 seems to be on track to tolerate WAI-ARIA markup mixed in with the HTML5 markup. Authors could meet the WCAG2 requirement with @aria-labelledby and @aria-describedby in a host language that doesn't have @alt or @longdesc. I am not advocating this change. But in terms of the feasible range of ways that HTML5 can support authors in meeting WCAG, even that is technically feasible. We need to look at the use cases that @alt handles badly or not at all, figure out how we are going to meet WCAG for those use cases, and then come back to see how the format spec across the board, including but not limited to the @alt attribute, supports the requirements that are set out in WCAG. I think that a better way to frame the argument is something like: 1. By the principles, HTML5 wants to support accessibility 2. By their charters, WAI groups (here WCAG) are the go-to experts in matters of accessibility 3. WCAG requires @alt (WCAG1) or the function that in HTML4 is provided by @alt (WCAG2) [editorial note -- add links] 4. By the principles, if it 'tain't broke, don't fix it. 5. Conclusion: barring the introduction of three fresh good reasons for a change, the failure of the HTML5 draft to make @alt on <img> an across-the-board requirement (even if sometimes it has the value of "") is a bug. Or do you have reasons? Does this work for you? Al > Best Regards, > Laura > > -- > Laura L. Carlson >
Received on Monday, 4 February 2008 19:24:32 UTC