W3C home > Mailing lists > Public > public-html@w3.org > July 2010

Re: Change proposals for ISSUE-31 and ISSUE-80

From: Steven Faulkner <faulkner.steve@gmail.com>
Date: Thu, 22 Jul 2010 12:33:21 +0100
Message-ID: <AANLkTinoWtd6OavHefLiMtuH5JlaI7_fH6ZHJuwSEKgM@mail.gmail.com>
To: Aryeh Gregor <Simetrical+w3c@gmail.com>
Cc: HTMLWG WG <public-html@w3.org>
Hi Aryeh,
there is also some info provided in the following surveys:
http://www.webaim.org/projects/screenreadersurvey/
 http://www.webaim.org/projects/screenreadersurvey2/

A paper [1] from 2005 by Chieko Asakawa (a researcher and developer of
assistive technology and accessibility testing tools at IBM research labs
Tokyo, who also happens to be blind) provides some useful data and
discussion about alt text usage.

She states:

> "*If there is no alternative text for these images, blind users will lose
> a lot of the information that is presented by using images. Alternative
> texts are extremely important for them to obtain this information from the
> Web and to navigate through Web pages."*
>
**
**
*3.1 Insertion of alternative texts*

> The use of images is rapidly increasing. Figure 1 shows the annual average
> number of images used in one page for 11 tested sites over the past 9 years.
> This shows that the number has increased more than four times during this
> period. *If there is no alternative text for these images, blind users
> will lose a lot of the information that is presented by using images.
> Alternative texts are extremely important for them to obtain this
> information from the Web and to navigate through Web pages. *All the
> guidelines and regulations mention providing alternative texts when images
> are used in a page. Figure 1 also shows the number of missing alt texts in a
> page. It increased from 1997 to 2000. However, it decreased suddenly in 2001
> from 13.2 images (38%) in 2000 to 9.1 images (19%) in 2001. Investigating
> the data, we found that all of the images on 5 tested Federal Agency sites
> had alt texts. US Section 508 became effective in June, 2001. This
> regulation apparently affected these numbers. In 2004, it appears that
> private companies also started inserting alt texts. The number of images
> without ALT text decreased to 3.1 images (7%) in 2005. This was affected by
> one of the news sites that had only inserted alt texts for 27% of the images
> (missing alt ratio 73%) in 2004, but that site had improved to 94% (missing
> alt ratio 6%) in 2005. The use of images has increased steadily, but the
> ratio for missing alt texts has been decreasing quite consistently among
> these test sites since 2000.This indicates that the Web accessibility is
> improving drastically.
>
The paper also discusses issues arising from inappropriate text
alternatives.

 [1] What's the *web *like if you can't see it? (PDF File, 633kb) [
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.59.8390&rep=rep1&type=pdf
]
 regards
stevef

On 21 July 2010 00:54, Matt May <mattmay@adobe.com> wrote:


> -----Original Message-----
> From: Aryeh Gregor
>
> > It
> > seems to me that authors who use alt text overwhelmingly do so just to
> > shut up validators, and I can't see how this helps anyone.  It's a
> > clear case of hidden metadata.
>
> > What data is there that directly demonstrates that alt text as
> > actually used on typical websites is helpful to blind people in
> > practice?
>
>
> Here, you've offered your opinion as a starting point, but demand "data" to
> counter it. I have to suggest that you're suffering from selection bias from
> working around people who place a higher value on validation than adhering
> to the spirit of the spec. My feel for things, which is likewise colored by
> working with my share of developers and designers, not to mention blind
> users themselves, is precisely the opposite. I'd suggest that more people
> produce meaningful alt text than fake it for the sake of a validator, but I
> don't see how anybody is going to be swayed either way.
>
> Instead, let's look at outcomes. In the case where @alt is mandatory, even
> when there are bad actors inserting bogus @alt values, it is exceedingly
> rare that such behavior does real harm to a user who can't see that image,
> relative to the possibility of not having it. In every other case, the
> presence of alt text, even when poorly done, either improves the situation
> for users who need it, or is easily ignored in favor of other repair
> techniques.
>
> And let's not overlook the people who, in the face of this constraint,
> actually do the right thing, when otherwise they'd have done nothing (which,
> by the way, answers your question regarding how blind users have benefited
> from mandatory @alt -- a benefit which must not be ignored in this
> discussion).
>
> In the case where @alt is optional, it will get left out with higher
> frequency. That's a tautology, at least for documents that validate. The end
> result is that users will lose the benefit of those who did something
> beneficial for consumers of alt text, even if it was only to validate. I
> think you'll find that benefit is perceived by those consumers to far
> outweigh the inconvenience of encountering useless alt text elsewhere.
>
> -
> m
>



-- 
with regards

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

www.paciellogroup.com | www.wat-c.org
Web Accessibility Toolbar -
http://www.paciellogroup.com/resources/wat-ie-about.html
Received on Thursday, 22 July 2010 11:44:32 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 9 May 2012 00:17:10 GMT