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

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

From: Gregory J. Rosmaita <oedipus@hicom.net>
Date: Sun, 24 Jun 2007 14:49:32 -0400
To: <public-html@w3.org>, wai-xtech@w3.org
Message-Id: <20070624175216.M22660@hicom.net>

aloha -- there are several essential reason for retaining LONGDESC:

1. RATIONALE for PRESERVING LONGDESC in HTMLx:

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 achieve...

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.)

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:

--- 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 known 
as the United Kingdom, which, this year, celebrates its 200th anniversary.
--- begin CAPTION content ---

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> 

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 ---

now THAT is a world of difference...  a caption pre-supposes that one
can also perceive the object being captioned (that is, put into context);
just as a TABLE without a summary pre-supposes that one can also 
perceive the data sets being table-ized



2. SUPPORT, EXAMPLES AND REASONS FOR THE LACK THEREOF:

although i don't believe in deprecating markup that exists for a 
VERY specific reason and needs no other justification than that 
it makes the web more meaningful to those with visual processing 
problems (not just the blind and legally blind, but those with 
degeneration of sight caused by advanced age) -- here is some 
actual data on the state of LONGDESC

JAWS has supported LONGDESC for at least 3 releases now (that is, 
since release 5, at least -- i have to check date-of-implementation) 
and there is a LONGDESC extension for FireFox...  

Longdesc extention for FireFox:
 * https://addons.mozilla.org/en-US/firefox/addon/273

this extension can be used with either FireVox or jon gunderson's 
Firefox Accessibility Extention (FAE)

FireVox: http://clc4tts.clcworld.net/

FAE: http://cita.disability.uiuc.edu/software/mozilla/

i believe window-eyes does support LONGDESC, as well, for i waited to 
change my kludged longdescription-wrapped-in-a-hyperlink (as well as 
using the LONGDESC attribute) to the LONGDESC attribute itself, sans 
wrapper, as can be seen at:

Longdesc Examples:
 * http://www.hicom.net/~oedipus/blog/pipe.html
 * http://www.hicom.net/~oedipus/hang.html
 * http://www.hicom.net/~oedipus/silly.html (there is a longdesced 
	graphic is between the level one page heading and the page's 
	mantra, "a mind, my son, is a wonderful 	thing to waste"

just as the contents of the summary attribute can be reused to provide 
a visual rendering of the summary's contents, so too can longdesc be 
yanked into an IFRAME (not my preference) or embedded as an OBJECT 
by the browser, so as to replace the image inline (show images, show 
longdesc, show alt text)

LONGDESC, would, i believe, have more mainstream support if the 
attribute used to point to a long description was HREF and not 
LONGDESC -- even HREFDESC would have been a more implemented 
iteration of LONGDESC as it is defined in HTML 4.01 (where hrefdesc 
is an attribute such as hreflang)

JAWS has supported LONGDESC for at least 3 releases now (that is, 
since release 5, at least -- i have to check date-of-implementation) 
and i believe window-eyes does support LONGDESC, as well, for i waited to 
change my kludged longdescription-wrapped-in-a-hyperlink (as well as 
using the LONGDESC attribute) to the LONGDESC attribute itself, sans 
wrapper, as can be seen at every site i've ever maintained; the 
unquestioning bending to the marketplace's will, by claiming that, since 
LONGDESC is not widely implemented, it should be deprecated, when it 
MUST be remembered that one of the MAJOR reasons that it is not more 
widely  supported by mainstream apps, is due to simple quote market 
realities  unquote -- there aren't enough of us who need LONGDESC and 
summary to market to, and therefore, any additional work that would 
inherently increase the accessibility of the product isn't needed or is 
assumed to be exclusively a third-party slash assisstive technology's 
responsibility...

don't forget, every day you age, your eyesight becomes a little less 
sharp than it once was, and if you survive to a ripe old age, you, too, 
may be dependent upon summaries for tables and long descriptions 
for graphical objects...

gregory.

POST SCRIPT ON THE WIKIPEDIA CITATION

PS: the use of the term "long description" is MISUSED by wikimedia; 
they mean that here is a list of the technical specs of the image, 
it's provenance, and permissions info -- NOT an actual description 
of the image; activating the "long description" on wikipedia leads 
only to an uncropped, full-sized graphic (in PNG format), with the 
option to download or view the actual SVG graphic; there is NOTHING
on wikipedia's "long description" pages that ACTUALLY describe the 
visual object itself, which is the purpose of LONGDESC -- not to 
provide provenance and a larger version of the image, credits, etc.
-- but to DESCRIBE the contents of the image as fully and completely
as possible.

---------- Original Message -----------
From: Lachlan Hunt <lachlan.hunt@lachy.id.au>
To: "Denis Boudreau (WebConforme)" <dboudreau@webconforme.com>
Cc: HTML WG <public-html@w3.org>
Sent: Sat, 23 Jun 2007 15:17:04 +1000
Subject: Re: dropping longdesc attribute

> Denis Boudreau (WebConforme) wrote:
> >>> Anyway, what rationale for dropping longdesc?
> >>
> >> IIRC, the reason for not including it was because very few authors 
> >> ever use it and, when it is used, it's not used properly.
> > 
> > OMG, that argument again. Who cares if it's useful.
> 
> If a feature isn't useful, there is no need for it.  But, since 
> I didn't say it wasn't useful, I'm going to assume you actually 
> meant who cares if it's used properly.  In that case, users 
> should care!  If it's not used properly, it doesn't benefit anyone.
> 
> > Quickly, let's trash h1 to h6 also - and let's not forget blockquote 
while 
> > we're at it.
> 
> The difference is that it's easy to find significant evidence to 
> justify the inclusion of h1 to h6 and blockquote.  It is not so 
> easy to find evidence for longdesc.
> 
> > Longdesc are essential for screen readers to provide long 
descriptions 
> > for graphics that otherwise could not be described because the nature 
of 
> > their content is just too complicated for a simple alt attribute.
> 
> A description of how it benefits users when used properly 
> doesn't constitute evidence of it being used properly.  Although 
> I'm quite sure users would benefit when they stumble across a 
> site that uses it properly, the question is does it get used 
> properly on a significant number of sites?
> 
> > Is there a single accessibility feature in HTML that will survive 
this 
> > group? Why is the left hand (html-wg) so bluntly ignoring what the 
right 
> > one (wai-wg) does?
> 
> Contrary to what you may think, I am not against accessibility 
> features in HTML.  We just have different opinions about the 
> best way to achieve it.  A lot of people seem to be advocating 
> the use of accessibility add-ons, like headers="" and 
> longdesc="".  However, a much better approach to accessibility 
> is to try and cater for it as part of the fundamental design,
>  not include it as an afterthought.
> 
> For that reason, I would prefer if accessibility could be 
> achived without things such as headers="" and longdesc="".  That 
> is why, for example, I essentially argued that it would be 
> better for accessibility if the headers attribute was redundant 
> in most (if not all) cases, since it would achieve the same 
> result with less effort from authors.  That is why so many 
> arguments against headers were trying and show that the example 
> tables provided did not need to use the headers attribute.  That 
> is why so much evidence got question because the headers 
> attribute was either redundant, or used wrongly.
> 
> >> More research on the issue is welcome.  In particular, evidence of 
> >> significant real world usage that provides a practical benefit to 
> >> users would be good.
> > 
> > And why should we bother? There has been a lot of efforts made 
> > previously by John (Folliot) and others in order to save summary and 
> > headers in tables. Still, the draft hasn't backed out one bit on the 
> > subject.
> 
> Ok, let's put this in perspective, shall we?  Hixie has about 
> 5000 unanswered emails (if not more) relating to hundreds of 
> unresolved issues, spanning over 3 years of development.  Rest 
> assured that the headers issue will be dealt with in due course. 
>  A final decision has not yet been made.
> 
> > Lachlan, why wouldn't you, for a change (as John had so eloquently
> > asked previously), provide evidence that this attribute is useless?
> 
> I am not arguing that it's useless.  My argument is simply that 
> there is not yet enough evidence to support its inclusion and 
> that we should investigate better alternatives, if possible.
> 
> Anyway, the following are the results of a search containing 
> about 100 billion <img> elements [1].  About 80 million (0.08%)
>  had a longdesc attribute specified.  Of those, about 33 million 
> were blank.  From this, we can conclude that about 41% of all 
> longdesc attributes are definitely used incorrectly.  That 
> leaves an upper bound of about 47 million 
> (0.047%) longdesc attributes in the sample that may be used 
> correctly. However, it is quite likely that many of those don't 
> contain a URI, or link to a description that isn't particularly useful.
> 
> But as I said, more research is welcome.  A final decision has 
> not been made on this issue.
> 
> > Those of us who work with screen reader users on a regular basis
> > know that this attribute is extremely relevant when it is used 
properly.
> 
> Then you should have plenty of evidence available to show where 
> it has been used in useful ways.
> 
> I know wikipedia uses it, but the question is, is it used in a 
> useful way?  This is an example taken from wikipedia:
> 
> <a href="/wiki/Image:Stargate_SG-1_Season_9_Title.jpg" 
> class="image" title=""><img alt="" 
> longdesc="/wiki/Image:Stargate_SG-1_Season_9_Title.jpg" 
> src="http://upload.wikimedia.org/wikipedia/en/thumb/d/d5/Stargate_SG-
1_Season_9_Title.jpg/250px-Stargate_SG-1_Season_9_Title.jpg" height="141" 
width="250"></a><br> <small>Stargate SG-1 intertitle (Seasons 9-10)
</small>
> 
> The longdesc attribute points to the same location as the link.  
> So, arguably, nothing would be lost if the longdesc was removed. 
>  It's also questionable whether the page it links to actually 
> qualifies as a long description.  The image pages on wikipedia 
> generally don't describe the image in any useful way for 
> assistive technology.  They usually just provide a larger 
> version of the image, copyright info, file history, etc.
> 
> [1] (Source: Unpublished Google internal survey of several 
> billion pages conducted in September 2006.)
> 
> -- 
> Lachlan Hunt
> http://lachy.id.au/
------- End of Original Message -------
Received on Sunday, 24 June 2007 18:49:42 UTC

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