- From: Michael Cooper <mcooper@cast.org>
- Date: Thu, 5 Oct 2000 13:55:26 -0400
- To: <w3c-wai-gl@w3.org>
Here's some comments on the WCAG draft. I haven't been following the process closely so I apologize if I say something that's already been discussed to death. Things that I don't mention here I thought were fine, though I think the suggestions in the open issues list have merit. 2.2: "Use style languages..." We might want, in this or another checkpoint, to say "use markup in such a way that user-defined stylesheets will work well." What I'm getting at is, if an author makes structural differentiation on the basis only of class attributes or something, a typical user style sheet, which will only reformat standard markup, might not see the differences. As much as possible, "plain" markup should be employed to maximize the effectiveness of user-defined style sheets. 3.2: "Use color, style, graphics to emphasize structure..." I think this is an important thing. In my experience, however, it has the _appearance_ of colliding with other guidelines (make sure colors contrast well, stylesheets degrade gracefully, graphics have textual alternatives, etc.). People don't get on first reading that it's actually saying "use color etc. but use it per other guidelines". A suggested wording might be "Use color, styles, and graphics, following applicable guidelines, to emphasize the structure of the document." The explanation block can go into that a bit, I can write a suggestion of people take this up. 3.9: "Define key terms... abbreviations and acronyms..." It says only the first instance needs to be expanded. I just need clarity on why that is. Is it because it is from then on the user agent's responsibility to know that it has been expanded, and know to present the expansion? Or is it on the theory that the user has already encountered the term and doesn't need it expanded again? I suggest that that might not be true for users with cognitive disabilities. Also, what if the user was skimming on the basis of structural elements or something? They might not have encountered the term where it was first expanded, and then be confused. If it is the user agent's responsibility to take care of that, these aren't issues, but I haven't seen anywhere that it formally is, and it might be a little much to expect them to identify repeat occurrences of something in the text stream that is not set apart with markup. 4.1: "Provide... navigation mechanisms..." Perhaps in the explanation of this, or _maybe_ as a new point, I would add "Provide clear notification on each page of the user's location within the site structure." I think that's important not to have the "lost" feeling especially when landing on a page as a result of a search. 5.3: "Use device-independent event handlers" It asks for examples. First is "active" (CSS pseudoclass) or "onactivate" (scripts) - should be triggered by either a mouse click, the enter key, or whatever other device function, though it isn't yet widely supported in browsers as being different from "onmouseclick" or "onkeypress". There are a number of DOM 2 events that _might_ qualify too: load, unload, abort, error, select, change, submit, reset, focus, blur, resize, scroll. In ER we suggest keyboard events as qualifying (focus equals mouseover), but that is actually just dependent on a different, more common, device and perhaps those shouldn't be included here. 6.2: "Avoid... blink or flicker..." First, the rationale for this should be in this document, and could be pretty much the same as in WCAG 1.0. Second, this seems to overlap with 3.10: "Minimize content that will interfere with the user's ability to focus." Maybe they should be combined, or 6.2 should be reworded to apply only to blinking/flickering that triggers seizures or freezes browsers, and the distracting effects of blink/flicker left in 3.10. If you want wording suggestions I'll put something together. 6.3: "Avoid causing pages to be refreshed..." This seems to be pretty much covered in 4.3: "Avoid methods that interfere with navigation", so I'd be inclined to remove this. Perhaps in its place, we should say "Provide alternate means of navigating to the target of page that is redirected automatically" - which is an issue and more in line with Guideline 6 (backwards compatibility). 6.4: "...enable the content to be processed..." I found the wording of the explanation hard to parse. How about "This requirement is espeically relevant when using a data format or markup language that is not widely supported in user agent software. Note also the discussion of backward compatibility in checkpoint 5.1." Lastly, two issues that weren't addressed that I think should be: Target size. Small target areas (created by small linked images or small image map regions, or in programmatic objects) for pointing devices should be avoided, as they can be difficult for people with manual disabilities to get to. I know it's possible to tab to such links but it is usually not convenient to do so for people who interact with the page spatially rather than serially. I also see that sort of thing might be more specific than the group wants to get in this guideline set, but I think it can fit in pretty well. Therefore, I propose a new checkpoint under Guideline 4 to read: [title] Do not use small pointing device targets. [explanation] Links or other functionality that depend on moving the pointing device to a small target may be difficult to reach. Users with fine motor difficulty or high screen resolution may require several tries to reach the target. When possible, targets should scale with the rest of page if the user chooses. Targets that are dependent on absolute pixel sizes, such as linked images and image map areas, should not be smaller than 5 pixels in either the vertical or horizontal dimensions, and should enclose at least 30 pixels. [MC: those numbers are arbitray, and on the small side I think] Second, the issue of allowing the user flexibility in font size, typeface, and color doesn't seem to be particularly addressed. I especially did not notice a prohibition against the use of absolute sizes. Perhaps it was left to the user agent to ignore absolute sizes at user preference? Opera is the only one I know that does (and Lynx of course for different reasons); MS IE does too but at the cost of losing all relative size differences, which may convey meaning, between different pieces of text. Or perhaps it is expected that the guidelines essentially forbid deprecated elements like <font>, and mandate replacable stylesheets so that isn't an issue? I'm not sure that's likely to be widely implemented in the near future, and anyway I think the guidelines should mention the issue so authors are aware of it. I could see this issue as being distributed among several checkpoints, or presented as new checkpoints, and will make suggestions on that if people agree it should be there. That finishes me off for now... Michael Michael Cooper Bobby Project Manager Technical Designer CAST, Inc. 39 Cross St. Peabody, MA 01960 Tel +1 978-531-8555 x265 TTY +1 978-538-3110 Fax +1 978-531-0192 Email mcooper@cast.org http://www.cast.org/ http://www.cast.org/bobby/
Received on Thursday, 5 October 2000 13:56:41 UTC