W3C home > Mailing lists > Public > w3c-wai-ig@w3.org > July to September 2002

RE: Support for LONGDESC

From: Jon Hanna <jon@spin.ie>
Date: Tue, 6 Aug 2002 16:05:44 +0100
To: <w3c-wai-ig@w3.org>
Message-ID: <NDBBLCBLIMDOPKMOPHLHMEGLEEAA.jon@spin.ie>

> > Also, as the longdesc file is handled as a standard HTML file using HTTP
> > by the browser, it is liable to be indexed by indexing spiders, so
> > potentially could be found as a result of a search query, without
> > appropriate context, navigational bars, etc.  (I appreciate that it can
> > be useful to find such information - I'm trying to think through the
> > implications).
>
> Again could be handled a couple of different ways, via robots.txt,
> .htaccess, <meta name="Robots" content="noindex,nofollow" />, etc.  All
> three if you're really paranoid! <grin>

There goes the baby as well as the bathwater!

Presumably if a search engine has matched a description of an image to a
search query then that image in some way satisfies the search. Indeed such
discovery for a search engine would likely be more reliable than is
available from most sites (which is why the image search is probably the
least dependable part of those search engine sites which offer one). The
text of a longdesc file can be considered metadata about the image after
all.

Rather than try to discourage such indexing, take advantage of it:

1. Provide navigation that makes the longdesc useful as a "first page" in
the site.
2. Provide machine-readable links to every document that you know uses, or
is very likely, to use the image, so the search engine can associate the
image with the original document:

<head profile="http://purl.org/DC/elements/1.0/">
	...
	<link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" />
	<meta name="DC.Relation.IsRequiredBy" content="blah.html" />
	<link rel="DC.Relation.IsRequiredBy" href="blah.html" />
	...
</head>
(or perhaps DC.Relation.IsPartOf or DC.Relation.IsReferencedBy as
appropriate), so there is at least a better chance of the search engine
associating the image it now has a description of with its primary context.
Received on Tuesday, 6 August 2002 11:04:49 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 19 July 2011 18:14:05 GMT