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Re: some reflections on @alt usage

From: Steven Faulkner <faulkner.steve@gmail.com>
Date: Thu, 21 Aug 2008 11:07:07 +0100
Message-ID: <55687cf80808210307j8e49ebbj87558c9c0bded49c@mail.gmail.com>
To: "Ian Hickson" <ian@hixie.ch>
Cc: "Al Gilman" <Alfred.S.Gilman@ieee.org>, "W3C WAI-XTECH" <wai-xtech@w3.org>

hi ian,

>There are two problems with this. One is that the descriptive
>identification of the non-text content would almost certainly be provided
>anyway, e.g. as the image caption, for all users, and thus including it in
>the alt="" attribute would be redundant, leading to "stuttering" (that is,
>content repetition).

Can you provide the the research to back up the claim that descriptive
identification would almost certainly be provided elsewhere?

The caption for such an image does not necessarily suffice  as the
text alternative, much more descriptive information can be provided
for disabled users who cannot view the image or have a vision
impairment that renders image blurred. Who are you to decide that this
information is not worthy of inclusion by mandating that the alt must
be of the form {}.


In the example below the alt provides descriptive information that may
be useful to visually impaired users. It provides information that
would be obvious to a sighted user but could not be ascertained by a
vison impaired user unless they asked someone to describe it to them.
That is the point of a textual alternative, to provide information to
a disabled user that cannot access the information themselves.

<figure>
<img src="/commons/a/a7/Rorschach1.jpg" alt="a black vertically
symmetrical shape, which contains 4 small white areas and 9 smaller
black blotches seperated from the main body of the shape.">
<legend>A black outline of the first of the ten cards
in the Rorschach inkblot test.</legend>
</figure>

> The following:
>
>   <p>What do you see in the following image?</p>
>   <p><img src=test.jpeg alt="A colour blindness test."></p>
>
> ...is semantically equivalent, for users without images, to the following:
>
>   <p>What do you see in the following image?</p>
>   <p>A colour blindness test.</p>
>
> Which is not at all equivalent.

WCAG does not mandate that the text alternative must be an
'equivalent', it accepts that this is not always possible, in which
case a description is the recommended text alternative.

> Could you give an example of such a page where one would have an image
> that cannot be described when the page is written but where the image
> nonetheless has enough associated data that the user would get confused?
>

examples:
http://www.flickr.com/photos/
http://www.flickr.com/photos/tags/australia/
http://www.flickr.com/explore/interesting/7days/


> Joshue has provided extremely useful usability studies that we have used
> to help guide the design of HTML5. However, with all due respect to
> Joshue, sometimes even his opinions contradict the evidence he provides.
> That is why it is more important to base our decisions on actual objective
> research. (I say this without meaning any ill will to Joshue at all, I am
> very thankful for all the research he has done for us so far.)

What josh provided was one set of videos, this in way way can be
considered a basis for any decisions, the study is in  no way
'scientific' or objective

> That is why it is more important to base our decisions on actual objective
> research.

All the decisions appear to be made by you, so the use of 'our' seems
incorrect here.

where is this 'objective research'??


> Asking me to speak to other experts is still an argument based on
> authority and not an argument based on research.


At the risk of repeating myself where is this research you have used ?


Talking about arguments based on research rather authority is
hypocritical as these issues are decided by you on the authority that
you have over the what goes into the HTML5 spec. You don't let lack of
research get in your way. So really it ends up that unless your
authority is circumscribed by the authority of the W3C, all the
decisions about what goes into the spec will continue to be made by
you, not by the HTML working group.

Under the present situation, the only hope for any input into the spec
without you calling the shots is at 'last call' when W3C member
organisations can formally object and stop the spec becoming a
candidate recommendation. I for one will be working with disability
organisations who are members of the W3C to this end.

As you are in control, the eventualities of the outcomes are down to you.

so be it.

stevef.




2008/8/20 Ian Hickson <ian@hixie.ch>:
>
> On Wed, 20 Aug 2008, Al Gilman wrote:
>> On 19 Aug 2008, at 5:35 PM, Ian Hickson wrote:
>> > On Tue, 19 Aug 2008, Al Gilman wrote
>> >
>> > > In the Rorschach test WCAG spells out what you should provide as a
>> > > text alternative.
>> >
>> > Could you elaborate? I haven't been able to find where in the WCAG
>> > documents it is made clear what could be said that would actually help
>> > accessibility here.
>>
>># [...] text alternatives at least provide descriptive identification of
>># the non-text content.
>
> There are two problems with this. One is that the descriptive
> identification of the non-text content would almost certainly be provided
> anyway, e.g. as the image caption, for all users, and thus including it in
> the alt="" attribute would be redundant, leading to "stuttering" (that is,
> content repetition). What does WCAG say the alternative text should be
> when the image is a key image, such as a Rorschach test, but the
> descriptive identitification is already provided elsewhere?
>
> Secondly, a descriptive identification of an image is _not_ a textual
> replacement of the image.
>
> The following:
>
>   <p>What do you see in the following image?</p>
>   <p><img src=test.jpeg alt="A colour blindness test."></p>
>
> ...is semantically equivalent, for users without images, to the following:
>
>   <p>What do you see in the following image?</p>
>   <p>A colour blindness test.</p>
>
> Which is not at all equivalent. The point of the image here is the image,
> the text "A colour blindness test" is not a replacement, it's not
> equivalent, and treating it as such makes the page highly confusing and
> even more inaccessible to users than necessary.
>
> In cases like these we need a mechanism that explicitly says "I know this
> is an image, don't replace the image with some text and pretend the image
> wasn't there".
>
>
>> > > > > 2. Don't say that this markup advice is for *important* images
>> > > > > where you don't know what to provide as a text alternate.  The
>> > > > > 'important' restriction is not appropriate.  The same markup
>> > > > > approach should apply for unimportant images where you don't
>> > > > > know that they are unimportant.
>> > > >
>> > > > Could you provide an example? When would there be an unimportant
>> > > > image for which alternative text is required (i.e. it's not
>> > > > decorative) and for which the alternative text isn't available?
>> > >
>> > > In the batch-upload scenario, the site wrapping the uploaded photos
>> > > doesn't know which files are key moments from the vacation and which
>> > > are useless blurs containing only a fuzzy swipe of the user's foot.
>> > > You don't know it's important until you know what is in the image
>> > > and what it contributes to the story it is embedded in.
>> >
>> > In the context of an HTML document, though, those pages are
>> > objectively important regardless of whether they may be unimportant in
>> > the context of the wider photoset. They are the "content" of the page,
>> > which is important by definition.
>>
>> No.  There is no objective importance.  Importance is for the user to
>> revise as they browse the page.
>
> I disagree. Regardless of whether the photo is in focus or not, anyone
> going to a photo's flickr page is always intending to look at that page's
> photo. There's never a case where Flickr would remove the photo from its
> own photo page.
>
>
>> > > > > if we are going to try to address this as a common case,
>> > > > > unknown-to-be-decorative images should be included and not just
>> > > > > other unknown-what-to-say images thought to be 'important.'
>> > > >
>> > > > How can the author not know if the image is decorative or not?
>> > >
>> > > See discussion of photo-upload scenario above.
>> >
>> > None of the photos are decorative in that example, and you know this
>> > ahead of time, before the photos have even been uploaded.
>>
>> No, the photos were bulk uploaded.  They are all the images the camera
>> retained.  You don't know how important they are because the person who
>> shot them has not reviewed them before they went into the online system.
>
> You may not know how important the user considers them, but you certainly
> _do_ know that in the context of the Flickr page, none of them are
> decorative.
>
>
>> When they haven't looked at the image, only pressed the shutter button
>> and uploaded the camera contents after three weeks of pressing the
>> shutter button.  It is the bulk-upload case.  It's your use case.
>>
>> The 'not possible' case has been justified on the basis of "we have to
>> tell the site pasting the user's undocumented image into a pro-forma
>> page what to do with the attribute."  This is what I mean by you are
>> splitting the author.  The original author is the vacationer pressing
>> the shutter button.  But they don't look at the image or add text to it.
>> The site puts it into some HTML pages.
>>
>> Do these have to be conforming?  To what?
>
> Conformance is how we say what is allowed and what isn't. We want to allow
> people to upload their images to the Web without looking at them.
> Therefore it has to be possible to mark up such a page in a conforming
> manner. That's just what conformance is.
>
>
>> > > > > And make it clear that the "human didn't bother" case is
>> > > > > included.
>> > > >
>> > > > According to HTML5, if the human didn't bother, the page isn't
>> > > > compliant.
>> > >
>> > > This is statement at variance with the attempt to cover the photo
>> > > upload case. I don't agree with this interpretation of the draft as
>> > > posted.
>> >
>> > The spec says:
>> >
>> > # When it is possible for alternative text to be provided, for example if
>> > # the image is part of a series of screenshots in a magazine review, or
>> > # part of a comic strip, or is a photograph in a blog entry about that
>> > # photograph, text that conveys can serve as a substitute for the image
>> > # must be given as the contents of the alt attribute.
>> >  -- http://www.whatwg.org/specs/web-apps/current-work/#a-key
>> >
>> > That seems pretty cut and dry to me.
>>
>> It has a gratuitous "when it is possible..."  So far all the 'not
>> possible' examples offered are either contradicted by what WCAG says
>> should be in the text alternative, or a closet 'didn't bother' as when
>> you say "We have to tell the site how to format it when the uploading
>> user didn't provide anything."
>>
>> Don't get me wrong.  My personal opinion is that we should still look at
>> what is the best non-conforming-to-WCAG thing to do in repair cases such
>> as the bulk upload.  And there is a live question as to whether this
>> belongs in HTML specification or WCAG techniques.  But we should take it
>> on.  However with a note that this is a "close, but no cigar" situation
>> as far as meeting accessibility standards.
>
> HTML5 will define how authors are to mark up their HTML5 pages. We're not
> talking about how to conform to accessibility standards, it's a given that
> if you haven't described the photo textually then there is no way for a
> text-only user to get an "accessible" experience. We're talking about what
> HTML5 should require of such authors.
>
>
> So far there have been three proposals for handling these cases:
>
>  * Saying that the alt="" attribute being omitted is that indication. This
>   causes problems because so many pages omit the alt="" attribute on many
>   unimportant images that user agents will likely want to use heuristics
>   on those images instead of always honouring the new semantic.
>
>  * Saying that special syntax in the alt="" attribute is the indication.
>   This has the problem that in some cases, people will use the syntax
>   unintentionally (e.g. with the {} proposal and latex alt text.)
>
>  * Introducing a new attribute just for this. This has a number of
>   problems: introducing attributes for such rare use cases isn't good
>   language design; the attribute would almost certainly be copied around
>   unintentionally by authors leading to it being at least as unreliable
>   as the special syntax if not more; it introduces a whole class of
>   extra conformance errors and complications, such as what to do when it
>   is used with or without the alt="" attribute; and, possibly most
>   important, nobody has come up with an obviously clear and unambiguous
>   name for this attribute.
>
> I'm leaning towards going back to the first of these.
>
>
>> > Could you cite the part of the spec that says that "not bothering" is
>> > a valid reason to not include alternative text? If there is anything
>> > that can be read that way, it should be fixed.
>>
>> "When it is possible..."
>
> Whether it is possible to do something is unrelated to whether the site
> author could be bothered to do it.
>
>
>> > > > > In particular, most accessibility experts will not agree that
>> > > > > the photo upload use case is one where the authoring tool could
>> > > > > not come up with something that is better than nothing.
>> > > >
>> > > > While this is clearly true (people calling themselves
>> > > > accessibility experts have stated they do not agree that a site
>> > > > accepting uploaded photos may not know what the image represents),
>> > > > I do not intend to pander to accessibility experts. My goal is to
>> > > > make the spec actually improve accessibility.
>> > >
>> > > in your own judgement, it would sound like. Your judgement in these
>> > > matters would be more accurate if you listened more attentively to
>> > > the institution of the WAI.
>> >
>> > With all due respect, I would rather base my judgements on verifiable
>> > research and on logical arguments than on blanket assertions that seem
>> > counter-intuitive.
>>
>> Well, the assertion that the un-screened image is 'objectively important
>> in the context of HTML' while in fact its importance is unknown in human
>> terms is more 'blanket assertion that seems counter-intuitive' than
>> 'verifiable research' or 'logical argument.'
>
> It seems pretty logical to me that in the context of a page designed to
> showcase an image, the image in question is important.
>
>
>> > > You seem to be assuming that the use can associate this information
>> > > correctly with the image.  The world in which the speech-only user
>> > > experiences a web page is smaller than that.  If the relationship of
>> > > the "also on the page" text to the image is machine-interpretable,
>> > > as for example 'legend' on 'figure' then the AT can help the user
>> > > make the association.  In the absense of such a formal relationship,
>> > > the redundancy can be more positive than negative.
>> >
>> > This is so diametrically opposed to my own experiences that I would
>> > need significantly more evidence of this to be convinced of it. Do you
>> > have any research you could show to demonstrate this remarkable
>> > assertion?
>>
>> This sounds as though your intuition is conditioned by your own
>> experience, and not from listening to blind or dyslexic users, or the
>> teachers of severly learning disabled people.
>>
>> Ask Joshue <joshue.oconnor@cfit.ie>.  He has spent far more time with
>> PWD using computers than you or I.
>
> Joshue has provided extremely useful usability studies that we have used
> to help guide the design of HTML5. However, with all due respect to
> Joshue, sometimes even his opinions contradict the evidence he provides.
> That is why it is more important to base our decisions on actual objective
> research. (I say this without meaning any ill will to Joshue at all, I am
> very thankful for all the research he has done for us so far.)
>
> Do you have or know of any research you could show to demonstrate this
> remarkable assertion that duplicating information improves accessibility?
> Asking me to speak to other experts is still an argument based on
> authority and not an argument based on research. Surely for such a major
> finding, there has been extensive documented research.
>
>
>> > > Something that "appears somewhere else on the page" doesn't meet the
>> > > technical requirements for a text alternative, as the user's working
>> > > memory of what is on the page is limited.
>> >
>> > I think this dramatically undersells the user. If a page contains a
>> > title, and a comment, and an undescribed image categorised as a photo,
>> > users would have no trouble associating the description comments and
>> > the title with the photo.
>>
>> Yes, but the rule is not limited to such simple pages.
>>
>> It would apply to an image that appears in a typically cluttered start
>> page.  And it is for that latter worst case that we should frame the
>> rule.
>
> Could you give an example of such a page where one would have an image
> that cannot be described when the page is written but where the image
> nonetheless has enough associated data that the user would get confused?
>
> The typical Flickr page is a good counterexample, since everything on the
> page is basically about this one image. Similarly, a start page with a
> Webcam would be a counterexample because it is highly unlikely that the
> Webcam image will have much metadata in parts of the page far away from
> the image itself.
>
> A concrete example would help demonstrate this case.
>
>
>> > > My personal preference would be to get that info in the DOM in formally
>> > > specified relationship to the image, and then see what makes sense to
>> > > put with the image itself that is terse, and serves two functions:
>> > > inform the user about the image and distinguish this image from others.
>> >
>> > Merely having the image on the page links the information to the image.
>> > Why is this not sufficient? I do not understand what user interface you
>> > are imagining that would make this more usable than what we have now.
>> > Could you elaborate? Why would a sighted user have less trouble
>> > associating disparate information in a Web page with an image on the Web
>> > page than a user without image support?
>>
>> [snip description of screen readers with which I am familiar]
>
> This doesn't answer the question. Extrapolating from what you refer to, I
> assume you are proposing that one could, while an image has been selected,
> press some key and have the screen reader offer links to other parts of
> the page, or even just read other parts of the page. But it's not clear
> that this is going to help. In the Flickr page example, for instance, the
> user already knows full well that the page is just a photo's page, and
> that all the information on the page is about the photo. He doesn't have
> to find the image to ask the screen reader to read the rest of the page.
>
> Indeed, I would posit that in any case where an image represents something
> for which there is no suitable replacement text but for which there is
> additional information available elsewhere on the page, the image will be
> the only such image on the page, and the page will be primarily about that
> image. Are there cases that contradict this?
>
> --
> Ian Hickson               U+1047E                )\._.,--....,'``.    fL
> http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
> Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
>
>



-- 
with regards

Steve Faulkner
Technical Director - TPG Europe
Director - Web Accessibility Tools Consortium

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -
http://www.paciellogroup.com/resources/wat-ie-about.html
Received on Thursday, 21 August 2008 10:07:43 GMT

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