- From: Wendy A Chisholm <wendy@w3.org>
- Date: Mon, 16 Oct 2000 17:15:31 -0400
- To: geoff freed <geoff_freed@wgbh.org>, <w3c-wai-gl@w3.org>, <w3c-wai-gl-request@w3.org>
Geoff, The original checkpoint used MathML as an example so I merely inherited that. The reason it did so, is that if you use an image to represent a mathematical equation, the alt-text will most likely not be read by a screen reader appropriately. Therefore, there is a need to provide the structure of the equation in markup. Neither Netscape Communicator nor MS Internet Explorer support MathML (that I'm aware of) but there are a whole bunch of other browsers that do. Please refer to: http://www.w3.org/Math/#Software In developing the guidelines, there was a strong voice from educators on this topic. --wendy At 04:22 PM 10/16/00 , geoff freed wrote: > >I propose we add the following to the errata: > >3.1 When an appropriate markup language exists, use markup rather than > >images to convey information. [Priority 2] For example, use MathML to mark > >up mathematical equations, and style sheets to format text and control > >layout. Also, avoid using images to represent text -- use text and style > >sheets instead -- except for logos and stylized navigation buttons used to > >create a distinctive look to a site. > >Is it wise to use MathML as an example here? Unless I'm missing out on >something, > there's no browser available to even display it. > >Geoff Freed >WGBH/NCAM > > > > > >On Monday, October 16, 2000, Wendy A Chisholm <wendy@w3.org> wrote: > >Hello, > > > >I have reread this entire thread both on IG and GL. I have given this a > >lot of thought. I expect disagreement with my conclusions. > > > >The question is: Does checkpoint 3.1completely outlaw the use of text in > >images. > ><blockquote> > >3.1 When an appropriate markup language exists, use markup rather than > >images to convey information. [Priority 2] For example, use MathML to mark > >up mathematical equations, and style sheets to format text and control > >layout. Also, avoid using images to represent text -- use text and style > >sheets instead. > ></blockquote> > > > >I have boiled the arguments into the following two positions: > > > >1. Checkpoint 3.1 of WCAG 1.0 is open to interpretation because people > >believe that adequate support for "an appropriate markup language" does not > >exist. CSS and SVG as languages exist, but the support for them does > >not. Therefore, it <em>should be</em> possible to use images to create > >text effects and as long as those images have alt-text a site can claim > >WCAG 1.0 AA Conformance. > > > >2. Checkpoint 3.1 of WCAG 1.0 is <em>not</em> open to interpretation > >because CSS and SVG exist and it is possible to create text effects in > >markup language. Therefore, it <em>should not be</em> possible to use > >images to create text effects and claim WCAG 1.0 AA Conformance. The > >primary reason for using markup is for the user to control the > >presentation, particularly to increase the font size. > > > >This is a priority 2 checkpoint. People can clearly claim WCAG 1.0 single > >A conformance and use text in images. > > > >Conformance to Double A becomes cloudy when we discuss logos or proprietary > >(or rare) fonts. It is possible to create logos in SVG, however SVG is > >not widely supported. As 3.1 is worded, "an appropriate markup language" > >exists, but the support does not. Therefore, as it is worded non of the > >W3C sites can claim higher than single A conformance because we include > >logos on the majority of our site. Note that many of those pages currently > >claim AAA conformance. Therefore, we can infer that we have been > >interpreting this checkpoint to mean that an appropriate markup language > >does not exist. > > > >In Opera it is possible to increase the font size of all text, including > >alt-text for images, up to 1000%. It is very easy to turn images on and > >off in Opera. One only need press "g" or click on a button on the menu > >bar. Therefore, if someone with low vision were using the page with opera > >and had difficulty reading the text in an image, they could easily toggle > >between seeing the image and reading the "magnified" alt-text. > > > >With the current state of browsers, I do not believe it is possible to > >avoid using text in images. Tools exist that will allow users to magnify > >the alt-text of those images. There are also tools that will read text out > >loud. > > > >I believe that many of the pages in the W3C site can continue to claim > >Triple A conformance to WCAG 1.0 because the appropriate markup language is > >not supported. As Lisa pointed out, our own WCAG conformance logo does not > >conform to checkpoint 3.1. Why? Because it is very important to establish > >the "brand" of both the W3C and WCAG, same with Bobby, and all > >other logos. > > > >By saying that people can not use logos and claim anything higher than a > >single A would make the other levels of conformance pointless. > > > >Therefore, I have to agree that sites may use text in images and claim > >Double A conformance. However, we should limit the use of text in images to > >only what is necessary for branding. I propose limiting text in images to > >logos and navigation buttons. It should not be possible to put an entire > >paragraph of text in an image and claim Double A conformance because you > >lose the structure of the document. > > > >The only case that remains that I find difficult to satisfy is the case > >that Cynthia pointed out where a company is using images in headings as > >part of branding. My concern is that people could claim "branding" for so > >many things to avoid converting something to markup. I believe this > >example violates another checkpoint, 3.5 Use header elements to convey > >document structure and use them according to specification. [Priority 2] > >Therefore, someone that wedded to appearance is probably only going to > >claim Single A and we should all be satisfied with that. > > > >I propose we add the following to the errata: > >3.1 When an appropriate markup language exists, use markup rather than > >images to convey information. [Priority 2] For example, use MathML to mark > >up mathematical equations, and style sheets to format text and control > >layout. Also, avoid using images to represent text -- use text and style > >sheets instead -- except for logos and stylized navigation buttons used to > >create a distinctive look to a site. > > > >Thoughts? > >--wendy > >-- > >wendy a chisholm > >world wide web consortium > >web accessibility initiative > >madison, wi usa > >tel: +1 608 663 6346 > >/-- > > -- wendy a chisholm world wide web consortium web accessibility initiative madison, wi usa tel: +1 608 663 6346 /--
Received on Monday, 16 October 2000 17:07:42 UTC