Re: Add partial sight/low vision to face to face agenda [was Are accessibility guidelines defined for the blind?

After thinking about this more, we could discuss the following techniques 
that would help determine if a page is accessible to someone with low vision:

1. how to determine if an image has text. if it does have text suggest that 
the text become the alt-text, perhaps also suggest that the author use 
style sheets.

2. check the page for high contrast color combinations - see the color 
study done by the ATRC in Toronto for more info. 
http://snow.utoronto.ca/readtest

3. check images for high contrast color combinations - this requires 
determining the colors used in the image.

4. I'm not sure what automated technique to suggest for this one: 2.1 
Ensure that all information conveyed with color is also available without 
color, for example from context or markup. [Priority 1]

--wendy


At 08:00 AM 5/3/00 , Wendy A Chisholm wrote:
>I disagree with this suggestion.  I believe the points that are being 
>discussed are a WCAG issue not a tool issue.  Now is the prime time to 
>take these issues to the WCAG working group as they have begun thinking 
>about revising the guidelines - particularly to address cognitive and 
>learning disabilities and to generalize the checkpoints so that they are 
>less HTML specific.
>
>Also, I don't believe enough credit is being given to what WCAG already 
>addresses in regards to low vision.
>
>Here are some excerpts from WCAG 1.0:
>
>Content developers must consider these different situations during page 
>design. While there are several situations to consider, each accessible 
>design choice generally benefits several disability groups at once and the 
>Web community as a whole. For example, by using style sheets to control 
>font styles and eliminating the FONT element, HTML authors will have more 
>control over their pages, make those pages more accessible to people with 
>low vision, and by sharing the style sheets, will often shorten page 
>download times for all users.
>
>Content developers must consider these different situations during page 
>design. While there are several situations to consider, each accessible 
>design choice generally benefits several disability groups at once and the 
>Web community as a whole. For example, by using style sheets to control 
>font styles and eliminating the FONT element, HTML authors will have more 
>control over their pages, make those pages more accessible to people with 
>low vision, and by sharing the style sheets, will often shorten page 
>download times for all users.
>
>(from the rationale of Guideline 1)
>This guideline emphasizes the importance of providing text equivalents of 
>non-text content (images, pre-recorded audio, video). The power of text 
>equivalents lies in their capacity to be rendered in ways that are 
>accessible to people from various disability groups using a variety of 
>technologies. Text can be readily output to speech synthesizers and 
>braille displays, and can be presented visually (in a variety of sizes) on 
>computer displays and paper. Synthesized speech is critical for 
>individuals who are blind and for many people with the reading 
>difficulties that often accompany cognitive disabilities, learning 
>disabilities, and deafness. Braille is essential for individuals who are 
>both deaf and blind, as well as many individuals whose only sensory 
>disability is blindness. Text displayed visually benefits users who are 
>deaf as well as the majority of Web users.
>
>Related Checkpoints:
>2.1 Ensure that all information conveyed with color is also available 
>without color, for example from context or markup. [Priority 1]
>
>2.2 Ensure that foreground and background color combinations provide 
>sufficient contrast when viewed by someone having color deficits or when 
>viewed on a black and white screen. [Priority 2 for images, Priority 3 for 
>text].
>
>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. Refer also to 
>guideline 6 and guideline 11.
>
>WAC note: if markup is used rather than images, text can be displayed 
>however the user chooses.  the user can choose size, color, and font.
>
>3.3 Use style sheets to control layout and presentation. [Priority 2]
>For example, use the CSS 'font' property instead of the HTML FONT element 
>to control font styles.
>
>WAC note: Again, this is giving control to the users.
>
>3.4 Use relative rather than absolute units in markup language attribute 
>values and style sheet property values. [Priority 2]
>For example, in CSS, use 'em' or percentage lengths rather than 'pt' or 
>'cm', which are absolute units. If absolute units are used, validate that 
>the rendered content is usable (refer to the section on validation).
>
>WAC note: this gets at the issue that Len mentioned.  If relative units 
>are used, when the font is increased the layout should adjust so that 
>there is not overlap.
>
>--wendy
>
>At 09:36 AM 5/2/00 , Leonard R. Kasday wrote:
>>I'd  suggest we add a discussion of partial sight/low vision to the face 
>>to face agenda to follow up on the points made by Peter.
>>
>>How about planning on an hour's worth after lunch on Thursday?  We would 
>>of course to either omit things now in that slot or move them and omit others.
>>
>>Len
>>
>>
>>At 09:36 AM 5/2/00 +0200, Peter Verhoeven wrote:
>>>Hi,
>>>
>>>This is not the first time that I bring up this point, but because I got
>>>less responce here a new try.
>>>
>>>The WAI often mentions numbers of people that having problems accessing
>>>web pages of the Internet. I often read the number 10 million. Are those
>>>10 million people blind? No, they are not blind at all. A lot of them
>>>are sight impaired which is not the same.
>>>In the "quick tips" I read only tips to make web pages accessible to
>>>blind, or maybe to make web pages accessible by using Lynx? If I check
>>>web pages with real accessibility problems for sight impaired with
>>>Bobby, it tells me Congratulations your web page is Bobby Appoved. I
>>>only need to do some manual checking, but all these checkpoints have
>>>nothing to do with things like universal design and color contrast.
>>>
>>>A growing number of web pages are designed "system dependent" that
>>>means, that if I don't have a special display resolution or font size
>>>setting a lot of information on the web pages is outside my screen and
>>>the only way to access is to track on bars.
>>>Some web designers don't like trackbars and disable them, so it becomes
>>>realy impossible to get some information on the page. But the page is
>>>Bobby approved (Congratulations!).
>>>
>>>In the statistics from visitors to my web site The Screen Magnifiers
>>>Homepage at http://www.magnifiers.org I see that 25% of my visitors have
>>>a display resolution of 640x480. We as sight impaired use this
>>>resolution often because the the text on hte screen is much lagere than
>>>in a higher resolution and setting a high resolution means that you need
>>>a more powerful system with more memory to let a screen magnifier
>>>performs well.
>>>
>>>A lot of these problems occurs in table and frames constructions and
>>>personaly I know it is often difficult to solve these problems also if
>>>you specified a table width of 640. If an image inside the table is
>>>larger than 640 or a word in a cell is larger the width of the table
>>>increases. A lot of web designers don't want to use percentages for
>>>defining table widh, because the lines of text becomes so long if
>>>someone has set a high display resolution. The problem "long line" seems
>>>to have a higher priority than "horizontal scrollbars".
>>>
>>>In my opinion a lot of these problems could be solved by the makers of
>>>browsers.
>>>In my opinion more attention is needed for accessibility problems that
>>>partially sighted have?
>>>
>>>Regards Peter Verhoeven
>>
>>--
>>Leonard R. Kasday, Ph.D.
>>Institute on Disabilities/UAP, and
>>Department of Electrical Engineering
>>Temple University
>>423 Ritter Annex, Philadelphia, PA 19122
>>
>>kasday@acm.org
>>http://astro.temple.edu/~kasday
>>
>>(215) 204-2247 (voice)
>>(800) 750-7428 (TTY)
>
>--
>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 Wednesday, 3 May 2000 11:31:48 UTC