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Re: Some TAG review of "Cool URIs for the Semantic Web"

From: Harry Halpin <hhalpin@ibiblio.org>
Date: Tue, 25 Sep 2007 11:39:09 -0400
Message-ID: <46F92B9D.7000201@ibiblio.org>
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Pat Hayes <phayes@ihmc.us>, Dan Connolly <connolly@w3.org>, Tim Berners-Lee <timbl@w3.org>, Technical Architecture Group WG <www-tag@w3.org>, Susie Stephens <susie.stephens@gmail.com>


    To go off on a tangent, maybe the reason the 303 redirect makes
sense (and this is the best reason I can think of) is that one sometimes
does not want logical statements to be mixed up between representations.
So, one may want to make a logical statement (in RDF, KIF, whatever)
about a Class of Persons. If the URI for the Class of Persons resolved
to a web-page created with a Creative Commons license, then one would
want to say that representation at the web-page URI  has a Creative
Commons license, not the Class of Persons - so in that case a 303
redirect from the Class of Persons URI to a distinct "web-page about the
Class of Persons" URI would be useful. However, one might also want to
make statements about the Class of Persons URI.

    So, if I were making up rules of thumb, I would say that if there is
a URI that is used to identify a resource one would want to make logical
statements about, and these statements do not apply to possible
representations of that resource, then one should use the "hash" or 303
redirection to separate  these URIs.  However, in practice I have a
funny feeling this might happen not so often, thus the advantage of the
"hash" technique that lets you both host representations while keeping
the URIs technically distinct.

Richard Cyganiak wrote:

> A more fruitful endeavour might be to shed some light on the
> relationship between a resource and its representation(s). Why can
> certain resources have representations, and others not? Who gets to
> associate representations with a resource?
A resource may or may not have multiple representations put their by the
owner (who obviuosly gets to associate representations with a resource,
or at least chose where a 303 direct might go), and IMHO any resource
should have representations that make its intended interpretation as
universally applicable as possible - as in have representations for
humans (in as many natural languages with requiste images as possible)
and also representations for machines using RDF or other SemWeb
languages. After all, the Web is a universal information space.
> Best,
> Richard
>> Pat
>>> [...]
>>>>  No, that "identify" is one case of "name". Which is true enough for
>>>>  government work, I will agree. But not all names are identifiers, is
>>>>  my point.
>>> On that and other matters, I'll perhaps reply separately.
>>> I'm still thinking it over.
>>> -- 
>>> Dan Connolly, W3C http://www.w3.org/People/Connolly/
>> -- 
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Harry Halpin,  University of Edinburgh 
http://www.ibiblio.org/hhalpin 6B522426
Received on Tuesday, 25 September 2007 15:39:24 UTC

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