Re: HTML5 alt conformance criteria clarifications requested

Hi Jgraham,

So what i can glean from you have written is that in cases where the
image is the sole content of a link the use of the  term "photo page"
in plain text without the {} would be the most appropriate value for
the alt attribute (in the absence of  a 'real text alternative').
as against the title/description which is used in flickr currently.

So coming back back to my original question: would the current usage
of the title/description by flickr be non conforming in HTML5?

regards
steve


On 16/08/2008, James Graham <jg307@cam.ac.uk> wrote:
> Steven Faulkner wrote:
>
> > hi jgraham,
> > yes, my bad you are correct on the title/description.
> >
> >
> >
> > > I believe the spec currently requires that flickr set @alt={photo} or
> > > similar.
> > >
> > >
> >
> > so does this mean it is what is required in these cases or you are not
> > clear on what is required?
> >
> >
>  Well I guess I was wrong in a sense because it depends entirely on what
> context the photo appears in. I was only considering the individual photo
> page case but actually there are a fairly large number of distinct cases.
>
>  On the user's home page (e.g. [1]) the photos are the sole contents of a
> link so per section 4.7.2.1.1. the alt text must "convey the purpose of that
> link". This suggests that the alt text in this case could be "Photo page" or
> similar. I guess adding the title of the photo e.g. "Photo page for Mario's
> Bike" would help in the case where someone wanted to query the images out of
> context but would be repetition in the case where the page was being read
> linearly. However I'm not sure that the spec has anything to say on the
> topic.
>
>  On the individual photo page (e.g. [2]) the photo is not a link and the
> image is clearly a key part of the surrounding content. Therefore Section
> 4.7.2.1.8. applies. At this point the alt text should contain a textual
> equivalent of the image unless no such alternate text is available. Clearly
> (from observing flickr) none of the fields provided are reliably used to
> provide textual equivalents of images. Therefore we are always in the case
> where there is no textual equivalent avaliable so we must supply an alt that
> provides a categorization of the image delimited by curly braces e.g.
> alt={photo} (there is no requirement that the exact string {photo} be used
> but it must be a classification of the image).
>
>  On some aggregate photo pages such as a group pool or a user's set (e.g.
> [3], [4]) the images are again the sole contents of links and so 4.7.2.1.1.
> again applies. In this case however, there is no context to give e.g. the
> name of the photo so using  something like alt="Photo Page for New Forest
> Pony". Arguably the text "Photo Page" is unnecessary although this does
> create a (relatively common) edge case when the photo has no title (note
> also the requirement to be careful here to avoid using titles that are
> delimited by curly braces directly in @alt).
>
>  On some search pages, explore pages calendar pages and explore front page
> (e.g. [5], [6], [7]) the photo is again the sole contents of a link but the
> other information about the photo is already supplied. This case is quite
> close to the user's stream page case.
>
>  Did I miss any cases?
>
>  [1] http://flickr.com/photos/jgraham
>  [2] http://www.flickr.com/photos/andrerabelo/70458366
>  [3] http://flickr.com/groups/utata/pool/
>  [4] http://flickr.com/photos/rebba/sets/72157594157565155/
>  [5] http://flickr.com/search/?q=sigur+ros&s=int
>  [6] http://flickr.com/explore/interesting/2008/08/15/
>  [7] http://flickr.com/explore/
>
>


-- 
with regards

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

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Received on Saturday, 16 August 2008 19:20:27 UTC