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Re: WCAG-ISSUE-30 (anchor alt vs. ing alt): Need better clarity on (cascading) alt requirements under 2.4.4 and 1.1.1 of linked images [HTML & ARIA Techniques TF]

From: Sailesh Panchang <sailesh.panchang@deque.com>
Date: Tue, 8 Jul 2014 09:47:28 -0400
Message-ID: <CAJi9Cqo2A-EpdoLHLbKK94MFYgDgj-tKLvOuJq_AFP_gF9_gxQ@mail.gmail.com>
To: Web Content Accessibility Guidelines Working Group <w3c-wai-gl@w3.org>
Hello David,
Perhaps the examples for H2 may offer some guidance.
As it is an image link, the anchor text +associated text (alt for img)
should adequately describe the link's purpose.
So it is priimarily SC 2.4.4.
I believe there cannot be any hard and fast rules about how much text
from the image should be included in the alt for the image link.
If the image contains  some important / critical info like "Offer
valid upto July xx" and is not part of the anchor text, it may be
included in the alt. Basically the essence of the image-text may be
included if the anchor text is not sufficiently detailed. So it is
alright to have a shortened  version of the image text in the alt.
Also depends on whether the image text is detailed on the target page.
But if that info is not available on  the target page at all, then
the alt may need to be more detailed.
Another factor is  the placement of the image within the anchor which
is part of UI design: does the reading order sound right with the alt
before or after the anchor text.
Another option is to place a null alt for the image, and supplement
anchor text with a title on the anchor as it will be exposed as
accessible description.
On the whole, the approach will be context specific and a matter of
judgment, I'd say.
Here are some examples.... the img can be anything - an icon or img with text.

<a href="#"><img src="images/addtocart2.png" alt="Add to cart" />Product 1</a>
<a href="#">Product 2 <img src="images/addtocart2.png" alt="Add to cart" /></a>
<a href="#" title="Add to Cart"><img src="images/addtocart2.png"
alt="" />Product 3</a>

Thanks,
Sailesh


On 7/7/14, Web Content Accessibility Guidelines Working Group Issue
Tracker <sysbot+tracker@w3.org> wrote:
> WCAG-ISSUE-30 (anchor alt vs. ing alt): Need better clarity on (cascading)
> alt requirements under 2.4.4 and 1.1.1 of linked images [HTML & ARIA
> Techniques TF]
>
> http://www.w3.org/WAI/GL/track/issues/30
>
> Raised by: David MacDonald
> On product: HTML & ARIA Techniques TF
>
> Suggest a discussion about overlap of requirements for images used as links
> in anchors which have to have alt text which meets 2.4.4 (and perhaps 1.1.1)
> vs alt for static images. These days most images are linked and there are
> many questions about the overlap between their requirements under 2.4.4 and
> there requirements under 1.1.1
>
> For instance, a linked image with an advertisement which is a photo along
> with some PhotoShop text on an insurance product... It needs to include the
> link destination, but does it also require the text that is in the ad, which
> is what we would require under 1.1.1? If so how much, in what priority...
> Equivalent purpose 1.1.1 vs link purpose 2.4.4
>
> I've heard an array of opinions on this type of thing, from minimalists who
> would just give it alt="Family Life Insurance", describing the linked
> product...  to those who require all of the text in the image to be repeated
> in the alt and to describe the photo of the family along with the link
> destination  even though it is not key in understanding the link
> destination. (Equivalent Purpose seems murky)...I would be glad for us to
> have a best practice... perhaps in association with Steve's alt text
> guidance for html5.
>
>
>
>
Received on Tuesday, 8 July 2014 13:47:55 UTC

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