WebAIM - Web Accessibility In Mind

E-mail List Archives

Re: LONGDESC in HTML5?

for

From: Vlad Alexander (XStandard)
Date: Sep 25, 2010 10:42AM

Steve wrote: "I cannot disagree more. the content of the alt attribute can be and is many things"

I don't see that. It's a really simple concept and if we keep it simple, people will then use it correctly.

Please don't take this personally (this is professional feedback), but I feel you are making alt more complex than necessary. Your 40+ page document on how to write alt text in HTML5 is way too complex and will unfortunately serve the purpose (directly or through derivative works) of scaring content authors/developers/tool vendors so that they will simply ignore alt or give it cursorily effort.

http://dev.w3.org/html5/alt-techniques/

Steve wrote: "The abscence of content indicates the image is decorative."

That fits with the definition of alt as a textual replacement for an image. In this case, the replacement text is blank because it is unnecessary given surrounding content.

Steve wrote: "If the image is the sole content of a link it is a description/label of the link target."

Let's put this to a test.

Test 1: In this case, should the author write alt to fit the target of the link or to fit surrounding content? I would argue that you should be able to add or remove a hyperlink from a document withing affecting the comprehension of that document. In other words, if I want to add or remove a hyperlink, I should not have to re-write content in the document. The only way to achieve this is to write content (be it normal text or alt text) to fit surrounding content.

Test 2: Paste the document into plain text such as Notepad or plain text email. Hyperlinks are removed. You are left with document content. So if alt is a "description/label of the link target" it's pretty useless here.

Steve wrote: "if the image is a photograph, diagram, illustration, cartoon, chart the alt may be a short description of the content."

That fits with the definition of alt as a textual replacement for an image. It all depends on the context (surrounding text). At this link I provide examples where alt is not a short description of a chart but instead text that is a substitute for an image to make surrounding context comprehensible.

http://rebuildingtheweb.com/en/how-do-we-save-longdesc/#c20100824114946

Take care,
-Vlad


-------- Original Message --------
From: Steven Faulkner
Date: 9/25/2010 6:08 AM
> Hi vlad,
>
> your wrote:
> "> The purpose of alt is not to "describe" images but to replace them.
> Alternate text can be quite different than a description of an image."
>
> I cannot disagree more. the content of the alt attribute can be and is many
> things:
> The abscence of content indicates the image is decorative.
> If the image is the sole content of a link it is a description/label of the
> link target.
> if the image is a photograph, diagram, illustration, cartoon, chart the alt
> may be a short description of the content.
> +others
>
> I respect yours and others views, but cannot accept that it is official or
> mandated anywhere that content of the alt attribute is always and can only
> be a "textual substitute", nor should it be, just as it should not be
> mandated that the presence of the image object in a HTML page must not be
> conveyed to users.
>
> regards
> stevef
>
>
>
> On 25 September 2010 10:42, E.J. Zufelt< <EMAIL REMOVED> > wrote:
>
>>
>> On 2010-09-25, at 5:25 AM, Vlad Alexander (XStandard) wrote:
>>
>>> I wrote: "Unfortunately, we are still talking about @alt and @longdesc as
>> "image descriptions" with the only difference being the number of characters
>> typed."
>>>
>>> Josh wrote: "What else would you like them to do?"
>>>
>>> Let's take a look at the text from this article:
>>> http://webaim.org/techniques/images/longdesc
>>>
>>> Article text: "In some instances, an image is too complex to describe in
>> a few words."
>>>
>>> The purpose of alt is not to "describe" images but to replace them.
>> Alternate text can be quite different than a description of an image.
>>>
>>> Article text: "Although there does not appear to be any limit to the
>> length of text in an alt attribute, alt text is meant to be relatively
>> short, so it would be an abuse of this attribute to write more than a few
>> words, or, at most, a few short sentences."
>>>
>>> Why? @alt is part of document content just like paragraphs. If you don't
>> impose arbitrary limits on paragraphs, why impose them on alt. The author
>> should decide on the length of alt text.
>>>
>>> Article text: "The answer, then, is to provide a brief alt text
>> description of the image and then provide a longer description elsewhere."
>>>
>>> This statement implies that alt and longdesc are the same except one is
>> longer than the other.
>>>
>>> We need to start calling content in the @alt attribute "textual
>> substitute" for an image, and content appearing in the @longdesc as a
>> "description" if we ever want alt to be authored correctly and longdesc to
>> be used.
>>>
>> I agree completely that we need to call content in the alt attribute
>> ""textual substitute" in order for there to be a clear differentiation, The
>> difference is * not * short and long description, but image replacement text
>> and image description text.
>>
>> Image description text is relative to the image, whereas image replacement
>> text is relative to a specific usage of an image within a specific piece of
>> content.
>>
>> I think that we also need to specify that alt ought to be able to point to
>> structured content, in case the image replacement needs to be structured
>> text (lists, etc.).
>>
>>
>> Everett
>>