- From: Charles McCathieNevile <charles@sidar.org>
- Date: Tue, 17 Aug 2004 19:38:35 +0300
- To: "Andy Budd" <andy@message.uk.com>, W <w3c-wai-ig@w3.org>
On Tue, 17 Aug 2004 16:57:40 +0100, Andy Budd <andy@message.uk.com> wrote: > I've discussed this issue on various accessibility, usability and web > design forums/mailing lists and all I get is personal bias. What I'm > interested in is hearing what the official WAI line is. Then you are on the wrong list. There is one place where WAI makes decisions like this, the WCAG working group. (Although the Protocols and Formats group smetimes works with them where there is overlap in scope, this doesn't seem to be such a case). Since the original checkpoiint on using relative units was written into the WCAG 1 recommendation, the group has made one revision, which was to clarify that for images and margins, there might be good reasons for sticking with other units as an erratum [1]. I would hope people are familiar with that, but wouldn't bet on it. As the person who (believes he [2]) proposed the checkpoint in the first place, it was intended to preclude things like a layout fixed in pixels with the font in em units. There has been a fair bit of discussion about this over the years, and I am not sure if there is a current consensus in the WCAG group. That is effectively what you have to have to claim there is an official WAI line on this. I interpret it as Tina, John and Patrick have suggested. The argument that convinces me of the need for fluid layouts is the wide range of actual screen sizes, which includes window sizes. I am familiar with users either squeezing everything into a small space to cope with things like tunnel vision, expainding the page to take up lots of space, so I can scan as much as possible of the structure while maintaining the text at a readable size (my personal requirements - based on relatively minor vision impairment and extremely inor motor impairments), expanding the text to a very large size (2 x 5 characters on the screen) through a wide variety of magnification mechanisms (seems all have some problems and some benefits). For what it is worth I include below what the EuroAccessibility group agreed to on the matter: Note their view on px... [[[ 3.4 Use relative rather than absolute units in markup language attribute values and style sheet property values. [Priority 2] Zeist Face-To-Face Meeting For any font styling or layout sizing don't use absolute units (px, pt, pc, in, cm). Are images in raster or vector formats. Check in the page? Check in the linked style-sheet? FONT STYLE CSS London Face-To-Face Meeting - Additions and amendments to the work done in Zeist Face-To-Face Meeting. Technology Specific Questions Have they used absolute units to size scalable elements. Have they used absolute units to position elements. ]]] - http://www.euroaccessibility.org/tf3_doc/CompiledWorkToDateOnChecklist.htm There is also some discussion along the lines of the WCAG erratum [2] - check around http://www.integriert-studieren.jku.at/eac-tf3/archiv/msg00070.html To sum up: I think there have been arguments based on accessibility that have been produced in your discussions - but it is sometimes easy to miss that they are not just a "personal bias" but one which is based on an identifiable accessibility need (albeit one that is too often left unexplained in the discussion :-( This is a place to sound out a community of interested people - the WCAG group is where you get the official WAI line on WCAG. Constructive participation in that group, detailed suggestions for improvement to their work, are always welcome. Baseless mudslinging is something they get too. On good days they can read into it whatever real point there might have been, but as far as I can tell it isn't generally the most effective way to get the group to see their way to solving problems with the guidelines. cheers Charles McCathieNevile [1] http://www.w3.org/WAI/GL/WAI-WEBCONTENT-ERRATA#entry-5 [2] I had a a brief look and found http://lists.w3.org/Archives/Public/w3c-wai-gl/1998AprJun/0251.html which seemed to be the first time the suggestion was made, plus an assertion that I wrote what amounts to the current checkpoint made a few months later when it was shiny and new - http://lists.w3.org/Archives/Public/w3c-wai-gl/1998JulSep/0092 is the end of that thread. I don't think I did a great job on the checkpoint, but I think I have explained what I meant in a way that has been very consistent over the subsequent 6 years. -- Charles McCathieNevile charles@sidar.org FundaciĆ³n Sidar http://www.sidar.org NB: Once upon a time I worked for WAI. Before that I worked for a University in Melbourne, and participated in WAI as a W3C Member representative. Currently I do neither. Although on specific occasions I will pass the agreed views of Sidar's WCAG 2 review group, normally to the WCAG working group, this is my personal opinion and I haven't asked, so don't know, if anyone in Sidar would endorse it. Let alone anyone else...
Received on Tuesday, 17 August 2004 17:39:11 UTC