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Re: alt text seen or not?

From: <pjenkins@us.ibm.com>
Date: Mon, 17 Jan 2000 15:33:08 -0600
To: w3c-wai-ig@w3.org
cc: kathleen.anderson@po.state.ct.us, David Poehlman <poehlman@clark.net>
Message-ID: <85256869.0076E811.00@d54mta08.raleigh.ibm.com>


David Poehlman wrote:
>if alt text is not available, should not there be an alternate
>somution?  for instance, in some cases, alt text is only available when
>you pass your <mouse> over the image.  with no mouse to pass, shouldn't
>that be rendered alternatively so that more people with disabilities can
>be accommodated?

Are you talking about in-line images (1), client-side image maps (2),
and/or JavaScript "mouse-overs"(3)?

The answer is dependent on what you mean by "rendered alternatively" and
who [the browser or assistive technology] is doing the rendering.  Perhaps
more importantly to consider is which version of which browser or assistive
technology is being considered and whether it is being "visually" rendered
[seen or not].

As we all know, the "rendered alternative" in many graphical browsers for
images (1) occurs when you turn off loading of images and the browser then
visually renders the alternative text in place of the images that were not
loaded. An assistive technology screen reader [if used] could then "render"
the alternative text in synthesized speech or Braille.  Many graphical
browsers ALSO visually render the alternative text of the image when the
mouse goes over the image.  The more interesting cases are image maps (2)
and JavaScript mouse-overs (3).

For client-side image maps (2) the answer is different depending which
browser + assistive technology combination we are talking about. I heard
arguments that because many graphical browsers render visually the "alt
text" of images (1), that they should also render visually the alt text for
the areas of the images maps (2).  These arguments were based on older
level assistive technologies AND / OR when graphical browsers have images
turned off for faster downloading and the sighted user can't see the
alt-text for the areas of the image maps, only the alt text for the whole
image, because many [all?] graphical browser doesn't visually render the
alt-text for the areas (2).  I do not consider either of these two
arguments "accessibility" related, but more to do with economics [can I
afford the time, money, or hardfile space] and the politics [willingness]
of upgrading or changing technology.  To be certain,  it is still helpful
for authors to provide the redundant set of text links, hence the Priority
3 guideline 1.5 in [WCAG], but also note the checkpoint 2.1 Priority 1 for
User agents to provide the access to all content including alternative text
[I assume for image maps?] at some point [UAAG]. Whether being visually
rendered is the intent of the checkpoint or by providing an equivalent
interface for the assistive technology meets the checkpoint is unclear to
me in this image-map case.

For JavaScript "mouse-overs" (3) I believe the responsibility for
"alternative rendering" belongs in the assistive technology.  There is also
the mobility view of the issue that needs to be considered here.  A sighted
person needs to be able to get the graphical browser to render the
"on-mouse over" event without directly using the mouse.  Some combination
of "mouse keys" support in the operating systems platform and additional
assistive technology that utilizes that support is needed to solve the
accessibility issue for the mobility impaired user.  The assistive
technology used by a blind person would also need to utilize that support
or perhaps a better interface that is being designed into the Document
Object Model (DOM).  The DOM interface would be exposed by the browser so
that the assistive technology could directly manipulate the document and
"render the equivalent" of the mouse-over to the user.  No need to simulate
hardware mouse actions or have the browser visually render the mouse-overs
with some new user interface.

I generally believe that there is and will always be a place for assistive
technology.  Although I support the goal or direction of universal
accessibility, I believe it is just that, a goal and direction, not a real
destination.  I also prefer to separate the economic and political concerns
from the pure "accessibility issues".   Keeping things separate makes it
easier to identify the party responsible, whether the browser, the
assistive technology, the user, or governments and society; thereby helping
us focus our efforts and directing the issues to whom best could solve
them.

[WCAG] http://www.w3.org/TR/WCAG10/#tech-redundant-client-links
[UAAG]
http://www.w3.org/TR/UAAG10/wai-useragent.html#tech-doc-content-access

Regards,
Phill Jenkins
Received on Monday, 17 January 2000 16:39:09 GMT

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