Re: table headers - clear description of problem

 David wrote:

> This is difficult to answer but there are AT vender representation on all
> the wai working groups.  They have been working with the WAI for years so
> much of the input you get from WAI representation is partly at least due to
> their input.  The AT venders also express their interest in what they
> support.

Yes, over a year ago on June 2007, Jim Allan, Chair UAWG wrote,
regarding the  headers attribute debate:

> User Agent Working Group comments:
>
> The 'headers' attribute is supported by the major screen readers used
> in the world (JAWS, WindowEyes, ??HAL/SuperNova-still waiting for a
> reply). WindowEyes uses the headers and id attribute combination.
> WindowEyes does *not* use the scope attribute. JAWS has support for
> headers/id, row and column span, and the 'axis' attribute.
>
> Assistive technologies, browser extensions, and tools that use DOM
> access also support the headers attribute and expose that information
> through their accessibility APIs and to their end users with
> disabilities and to developers. Examples of this include Firefox
> extensions like FireVox and the University of Illinois Firefox
> accessibility extension, and developer tools like Parasoft's WebKing
> and IBM's RAVEN tool
> (http://www.alphaworks.ibm.com/tech/raven).
>
> In addition, platform accessibility APIs such as IAccessible2 on
> Windows, ATK/AT-SPI on Linux, and the Java accessibility API all have
> functions for getting the row and column headers. The headers
> attribute, scope attribute, and TH all provided explicit, engineered
> ways for browsers to get row and column headers and expose that
> information to assistive technologies through the accessibility APIs.
> Without these, the browsers and assistive technologies are forced to
> resort to heuristics such as font styling and location (topmost and
> leftmost cells), which is insufficient for complex tables with
> spanned and multiple row/column headers.
Source:
http://lists.w3.org/Archives/Public/wai-xtech/2007Jun/0021.html

Support for scope and headers attributes in assistive technologies: June 2007
By Working Group members:
http://esw.w3.org/topic/HTML/TableAccessibility

headers/id Testing (Bug 5822): Summer 2008
> The headers/id mechanism provides needed functionality. It allows
> assistive technology to speak the headers associated with each data
> cell when the relationships are too complex to be identified using
> the th element alone or the th element with the scope attribute.
>
> Headers/id allowed the assistive technology combinations tested to
> successfully announce relationships 5 out of 6 times.
>
> Scope failed 6 out of 6 times. The failure of support for scope means
> that scope is currently not an effective option.
>
> Although it is widely known that scope isn't well supported by
> assistive technology [1 2 3 4 5], its use is strongly recommend,
> because it's easy to author, works with simpler data tables, and
> support is likely to improve.
Source:
http://esw.w3.org/topic/HTML/TableHeadersTestingBug5822#head-4dd98a1e6b2646ef8c2be83dd7b6c93622e25f4b

Best Regards,
Laura
-- 
Laura L. Carlson

Received on Tuesday, 26 August 2008 14:30:13 UTC