Re: HTML5 alt conformance criteria clarifications requested

Actually, flickr must be corrected.  Alt is required and it is clear what it 
is meant to do and if the image is that important, alt with meaning or 
description must be provided.

----- Original Message ----- 
From: "James Graham" <jg307@cam.ac.uk>
To: "Steven Faulkner" <faulkner.steve@gmail.com>
Cc: "Ian Hickson" <ian@hixie.ch>; "W3C WAI-XTECH" <wai-xtech@w3.org>; 
<public-html@w3.org>
Sent: Saturday, August 16, 2008 1:33 PM
Subject: Re: HTML5 alt conformance criteria clarifications requested



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/

Received on Sunday, 17 August 2008 15:27:39 UTC