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RE: Clarifying what a URL identifies (Four Uses of a URL)

From: Dare Obasanjo <dareo@microsoft.com>
Date: Tue, 21 Jan 2003 20:47:10 -0800
Message-ID: <B885BEDCB3664E4AB1C72F1D85CB29F804B7C830@RED-MSG-10.redmond.corp.microsoft.com>
To: "Michael Mealling" <michael@neonym.net>
Cc: "Tim Bray" <tbray@textuality.com>, "Sandro Hawke" <sandro@w3.org>, "David Booth" <dbooth@w3.org>, <www-tag@w3.org>, "Roy T. Fielding" <fielding@apache.org>, "Dan Connolly" <connolly@w3.org>

> -----Original Message-----
> From: Michael Mealling [mailto:michael@neonym.net] 
> Sent: Tuesday, January 21, 2003 5:59 PM
> To: Dare Obasanjo
> Cc: Tim Bray; Sandro Hawke; David Booth; www-tag@w3.org; Roy 
> T. Fielding; Dan Connolly
> 
> There's an intended difference between how other people use 
> an identifier and how you, the entity with authority over 
> that identifier, intends it to be used. I can claim that 
> http://www.25hoursaday.com is actually an identifier for me 
> but since I'm not authoritative for it no one is going to 
> believe me....

On the Web you cannot control how people will use an identifier. A
Semantic Web that is as limited as you describe would be particularly
useless in my personal opinion since it means only authorities that own
a resource can make statements about it. I hope no one actually working
on making the Semantic Web a reality has such a limited view of it. 
 
> > > It's a formalism.  The Web Architecture has a formalism called a 
> > > "Resource" which is the one thing that corresponds to each URI.
> > 
> > This statement is meaningless and yet W3C TAG members keep 
> repeating it.
> > What is the one resource that the URI 
> "http://www.w3.org/Consortium/"
> > identifies? 
> 
> The Resource that has that identifier. You can point to it, 
> it just is by virtue of the URI existing. Its a platonic 
> 'Resource'. It doesn't exist physically or virtually. It just 
> _is_. Things can claim to be representations of it, but 
> nothing can ever actually _be_ it.

This is circular reasoning which doesn't answer the question being asked
but pretends it doesn't exist. It may work fine to spout this answer
when designing a system for retrieving network addressable documents off
of remote  machines since it is primarily inconsequential to this
scenario but for knowledge representation this ambiguity is
unsatisfactory. Sandro has already done a good job of showing examples
of how this breaks down and the only counter examples I've seen are
either attempts to ignore the problem or point out that it works fine
for grabbing files of the network using HTTP. 


-- 
PITHY WORDS OF WISDOM 
An expert is one who knows more and more about less and less until he
knows absolutely everything about nothing.                            

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Received on Tuesday, 21 January 2003 23:48:00 GMT

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