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Re: Image description extension review

From: Charles McCathie Nevile <chaals@yandex-team.ru>
Date: Sun, 18 Nov 2012 13:18:18 +0100
To: public-html-a11y@w3.org, 'Léonie Watson' <tink@tink.co.uk>, "David MacDonald" <david100@sympatico.ca>, "Charles McCathie Nevile" <chaals@yandex-team.ru>
Message-ID: <op.wnyxss1yy3oazb@v3-151-181.yandex.net>
Without my chair hat...

So to restate here: I think we are on the same page about how alt should  
be used - but at some point we should clarify the examples in the longdesc  
spec.

Do you think we should publish the First Public Working Draft now, before  
we fix the examples, or do they need to be fixed first?

I think there is some confusion about what "longdesc on the same page"  
means in implementation.

Can you try the attached test case with JAWS?

And again do you think that we can publish a First Public Working Draft  
now, or need to fix this first.

Just a reminder, there is effectively an absolute minimum of 30 days  
between First Public Working Draft and Last Call if there is any  
difference between them, due to the Patent policy. It can of course be  
longer. In that time I personally think we can effectively deal with these  
problems, which is why I believe we are fine to go with the draft now. But  
of course the Task Force can always consensus that is different from my  
personal thoughts on the matter...

cheers

Chaals

On Sun, 18 Nov 2012 01:28:05 +0100, Charles McCathie Nevile  
<chaals@yandex-team.ru> wrote:

> On Sat, 17 Nov 2012 13:03:59 +0100, David MacDonald  
> <david100@sympatico.ca> wrote:
>
>>
>> Hi Chaals
>>
>>
>> I put up a test page:
>>
>> http://www.davidmacd.com/test/longdesc.html
>>
>>
>> -JAWS 13 doesn’t support longdesc on the same page in IE9,
>
> So I should clarify what we mean by that.
>
> In your results, JAWS opens a page at the point where the longdesc is,  
> right? Then you close it and you're back at the image?
>
> That's what happens in Opera and iCab when longdesc uses an internal  
> link. It possibly isn't ideal, but it is consistent so it should not  
> surprise users. And it gets >them to the longdesc.
>
>>
>> - JAWS 13 and FF14, neither example opens.
>> -JAWS 13 in Chrome 23.0.1271.64m: Neither example opens.
>
> That's strange. In the test case I had I made the page long - bigger  
> than a screenful, with a lot of separation between the image and its  
> description so it was clear >whether I had arrived at the reference  
> point.
>
>>
>>> I think there is a lot of advice to use null alt text for decorative  
>>> images. But there is reason such images should not have a longdesc.
>>
>>
>> I think we have our wires crossed. I was commenting on your first  
>> example:
>>
>>
>> <!-- pointing to something internal to the page -->
>> <img src="http://example.com/image" alt="" title="photo"  
>> longdesc="#photo1">
>>
>>
>> My concern is that the example is using null alt text on a  
>> non-decorative image.
>
> We don't have our wires crossed. That example was imagined as a  
> decorative image that is nevertheless described. I think it would be  
> good to clarify that.
>
> cheers
>
>>
>> There is currently no precedence for that, I would suggest. Current  
>> practice is to provide a short description AND a long description >>for  
>> images requiring long description. This is what is done in example H45  
>> in WCAG.
>>
>>
>> Cheers
>>
>> David MacDonald
>>
>>
>> CanAdapt Solutions Inc.
>>
>>  "Enabling the Web"
>>
>> www.Can-Adapt.com
>>
>>
>> From: Charles McCathie Nevile [mailto:chaals@yandex-team.ru]Sent:  
>> November-17-12 3:12 AM
>> To: public-html-a11y@w3.org; 'Léonie Watson'; David MacDonald
>> Subject: Re: Image description extension review
>>
>>
>> On Fri, 16 Nov 2012 22:38:57 +0100, David MacDonald  
>> <david100@sympatico.ca> wrote:
>>
>> Hi Chaals
>>
>>
>> On the call you had mentioned that longdesc pointing to an anchor on  
>> the same page is included in the HTML4 spec. I’m sorry but I’m >>unable  
>> to find any reference or example in HTML 4 of Longdesc referring to  
>> information (an anchor id) on the same page.
>>
>>
>> It's a URI - a link. That can be relative or absolute, including  
>> pointing to something else in the same page. It's common practice to  
>> have links to somewhere else >>in a page. There is very little in the  
>> HTML 4 spec about the precise mechanics of the link. But my testing  
>> showed that browsers which implemented longdesc >>assumed it should  
>> work for all URIs including links within the page.
>>
>>
>>>
>>> Nor can I find any recommended advice to use null alt text (alt=“”) on  
>>> an image that has a longdesc...
>>
>>
>> I think there is a lot of advice to use null alt text for decorative  
>> images. But there is reason such images should not have a longdesc.
>>
>>
>>>
>>> Nor are there any example techniques in WCAG showing this use of  
>>> longdesc or of null alt text.
>>>
>>> http://www.w3.org/TR/2012/NOTE-WCAG20-TECHS-20120103/H45
>>
>>
>> If I get time I can offer some.
>>
>>
>>>
>>> In 10 years on the WCAG team and weekly calls, I’ve never heard this  
>>> use case of Longdesc discussed, nor in 14 years in the field >>>have I  
>>> ever seen it done.
>>
>>
>> OK. I've done it, but I can't think of any examples I have available in  
>> public.
>>
>>
>>>
>>> I’m fine with the longdesc extension... but I think we either need to  
>>> demonstrate that this use case exists in the real world and is in  
>>> >>>HTML4,
>>
>>
>> The use case of longdesc within a page? There have been arguments  
>> raised many times that longdesc is deficient because it doesn't allow  
>> for this use case >>(which is simply untrue). If the people who are  
>> opposed to longdesc think this use case is important, that's good  
>> enough for me.
>>
>>
>> As for the use case of long description fora  purely decorative image,  
>> I think that's easy to establish. And it is already accepted that such  
>> images should have null >>alt. The interesting point that perhaps we  
>> should make in the spec is to consider this case when ensuring  
>> discoverability.
>>
>>
>> cheers
>>
>>
>> Chaals
>>
>>
>>>
>>> or we have to acknowledge that it’s a new behaviour for Longdesc.  I  
>>> also don’t think we should introduce null alt text for anything >>>but  
>>> decorative images... so far automated checkers rightly flag null alt  
>>> text to ensure it’s purely decorative... in the future we may >>>need  
>>> to expand the use of null alt text for cases when there is another  
>>> type of text alternative such as figcaption, aria-describedby,  
>>> >>>longdesc, etc.. but I don’t think such a precedence currently  
>>> exists.
>>>
>>>
>>> HTML4 references
>>>
>>> http://www.w3.org/TR/REC-html40/struct/objects.html#adef-longdesc-IMG
>>>
>>> http://www.w3.org/TR/REC-html40/struct/objects.html#adef-alt
>>>
>>> http://www.w3.org/TR/REC-html40/appendix/notes.html#accessibility
>>>
>>>
>>>
>>>
>>> Cheers
>>>
>>> David MacDonald
>>>
>>>
>>> CanAdapt Solutions Inc.
>>>
>>>  "Enabling the Web"
>>>
>>> www.Can-Adapt.com
>>>
>>>
>>> From: Charles McCathie Nevile [mailto:chaals@yandex-team.ru]Sent:  
>>> November-15-12 9:08 PM
>>> To: public-html-a11y@w3.org; Léonie Watson
>>> Subject: Re: Image description extension review
>>>
>>>
>>> On Fri, 09 Nov 2012 21:41:55 +0100, Léonie Watson <tink@tink.co.uk>  
>>> wrote:
>>>
>>> Hello,
>>>
>>>
>>> A few thoughts, mostly editorial.
>>>
>>>
>>> Mostly I've adopted or adapted your suggestions.  
>>>
>>>>
>>>> Introduction...
>>>>
>>>>
>>>> The code examples all have null alt attributes. Could they be more  
>>>> practical examples?
>>>
>>>
>>> Actually only one had a null value, the others had something but in  
>>> parentheses so I removed them and cleaned them a tiny bit. I'd be  
>>> happy for people to >>>propose better examples...
>>>
>>>
>>>>
>>>> Also wonder whether some best practice examples of longer  
>>>> descriptions would be helpful? The extension may not be the right  
>>>> >>>>place for them, but a separate note might do the trick.
>>>
>>>
>>> Steve also suggested this. For now I put it in a note as out of scope,  
>>> with a question about whether it would make sense to link to some  
>>> other document...
>>>
>>>
>>> Thanks for the review. I updated the document:  
>>> http://dvcs.w3.org/hg/html-proposals/raw-file/default/longdesc1/longdesc.html
>>>
>>>
>>> cheers
>>>
>>>
>>> Chaals
>>>
>>>
>>> --
>>> Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
>>> chaals@yandex-team.ru Find more at http://yandex.com
>>
>>
>>
>>
>>>> --
>>
>> Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
>> chaals@yandex-team.ru Find more at http://yandex.com
>
>
>
> --Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
> chaals@yandex-team.ru Find more at http://yandex.com



-- 
Charles McCathie Nevile - Consultant (web standards) CTO Office, Yandex
chaals@yandex-team.ru Find more at http://yandex.com



Received on Sunday, 18 November 2012 12:18:52 UTC

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