W3C home > Mailing lists > Public > public-html@w3.org > June 2007

Re: rationale for preserving longdesc in HTMLx [Re: dropping longdesc attribute]

From: Bill Mason <w3c@accessibleinter.net>
Date: Sun, 24 Jun 2007 20:09:39 -0700
Message-ID: <467F31F3.7090800@accessibleinter.net>
To: public-html@w3.org

Gregory J. Rosmaita wrote:
> aloha -- there are several essential reason for retaining LONGDESC:
> my mainstream arguement for LONGDESC is that there is a screaming
> need for it amongst academics and educational institutions, as more
> and more course content migrates to the web or intranets, equal access
> DEMANDS that they provide a meaningful long description...  i have
> been asked about this issues inummerable times by educators and
> developers of educational software, at symposia, workshops, and via
> email, which usually sparked by one of my archived impassioned pleas
> on the topic of longdesc, it's importance, and what it needs to 
> academics constantly complain to me that if they are to teach students
> without vision or with very low vision, they need more than ALT or
> CAPTION -- they need to describe the subtleties of the image being
> presented as content for those who cannot see the content, and those
> who have found a longdescription helpful, as a key to the symbolism
> contained in the image; or as a means of expounding on a static image
> of a map (such as of a migration, a battlefield, a schematic of a subway
> system, etc.)

Unfortunately the rest of your example has no such subtle needs of the
image in question.

> a few months ago, i was asked advice on how to provide meaningful alt
> text to a UK flag that is used to indicate resources in english, without
> the quote english english unquote redundancy...  i suggested "British"
> for the alt-text, so that the listener would hear "British English" (the
> page encoding was en-uk), and provided an extensive longdescription
> from memory to describe the Union Jack; this is particularly pertinent
> when a CAPTION (championed by some over longdesc) is used to
> illustrate a british flag -- the caption might read:

A blank ALT attribute would have been equally sufficient, since:

* presumably the resource was not written specifically in British
English -- otherwise the author would have not had this problem to solve
since he could have had "British English" without fear of difficulty or

* The text "English" immediately following the image acts as the
equivalent of an ALT attribute text.

> --- begin CAPTION content ---
> The Flag of Union has been the official flag of the United Kingdom since
> the Act of Union of 1807, which created the modern political entity 
> as the United Kingdom, which, this year, celebrates its 200th 
> --- begin CAPTION content ---

What would such text have to do with the image being used as an icon to
indicate content presented in English?

> now, compare that to the longdesc i recommended in the excerpt below:
> --- begin quote from post to webmaster ---
> Q: what is the purpose of the icon?
> A: to represent the english language; therefore, in the interest of
> both aural terseness and aural completeness, i would have advised
> you to do this:
> <th lang="en">
> <img src="ukflag" alt="British" longdesc="ukflag_longdesc.html" />
> English
> </th>

Unless the resource being referenced is specifically in British English
(and not just 'generically English'), this is a somewhat misleading
label to apply.

I would again say a blank ALT text would have sufficed, as would have
making the image a CSS background image, because....

> with a description of the british flag as the contents of the
> longdesc target, provided you contextualize:
> --- begin LONGDESC ---
> The flag of the United Kingdom is used on this site to indicate
> resources that are in the English language.
> The flag of the United Kingdom is commonly known as the Union Flag,
> or Union Jack.  It is the national flag of the United Kingdom
> of Great Britain and Northern Ireland. The flag's design dates from
> January 1, 1801, as a symbol of the Act of Union of 1800, which
> merged the Kingdom of Ireland and the Kingdom of Great Britain (until
> 1707, the United Kingdoms of England and Scotland), to form the
> United Kingdom of Great Britain and Ireland.
> The flag symbolically uses the national flags of England, Scotland,
> and Ireland to form a single flag comprised of:
>   * the flag of Scotland, which bears Saint Andrew's cross:
>     a white X on a blue field; and
>   * the flag of Ireland, which bears Saint Patrick's cross:
>     a red X on a white field;
>   * the flag of England, which bears Saint George's cross:
>     a red cross on a white field;
> the flag of Scotland forms the bottom layer of the Union Flag. Over
> Saint Andrew's white cross, the red cross of Saint Patrick is
> superimposed, on top of which is a white-bounded red cross of Saint
> George.
> --- end LONGDESC ---
> --- end quote from post to webmaster ---

...this is completely irrelevant LONGDESC, unless the site's audience is
readers interested in the history and evolution of flags.  (And if it
is, this information should be in a resource available via conventional
means, not only addressable through a LONGDESC.)

Given that LONGDESC is for:

* "...a long description of the image. This description should
supplement the short description provided using the alt attribute." [1]
* "...complex content (e.g., a chart) where the "alt" text does not
provide a complete text equivalent...." [2]
* "[providing] information in a file designated by the longdesc
attribute when a short text alternative does not adequately convey the
function or information provided in the image." [3]

The history of the flag has nothing to do with its function/purpose on
the page as an HTML element, does not fulfill a need not being handled
by the short description, and arguably the image shouldn't even be on
the page as an HTML element.

Bill Mason
Accessible Internet

[1] http://www.w3.org/TR/html401/struct/objects.html#adef-longdesc-IMG
[2] http://www.w3.org/TR/WAI-WEBCONTENT/#tech-text-equivalent
[3] http://www.w3.org/TR/WCAG20-TECHS/#H45
Received on Monday, 25 June 2007 03:55:19 UTC

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