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

From: Bill de hÓra <dehora@eircom.net>
Date: Thu, 23 Jan 2003 12:37:31 +0000
Message-ID: <3E2FE20B.6090801@eircom.net>
To: Tim Bray <tbray@textuality.com>
CC: Sandro Hawke <sandro@w3.org>, Michael Mealling <michael@neonym.net>, David Booth <dbooth@w3.org>, www-tag@w3.org, "Roy T. Fielding" <fielding@apache.org>, Dan Connolly <connolly@w3.org>

Tim Bray wrote:


Tim,

> On the other hand, using the same URI to mean different things is a Bad 
> Thing and leads to confusion and misbehavior not only at the Semantic 
> Web level but in terms of general human utility.  When you say that 
> http://example.com/moby represents Moby Dick you need to be clear 
> whether you mean Melville's novel in the abstract, some particular copy 
> on a shelf, the online Gutenberg text, a record in a particular library 
> catalog, or a fictional cetacean.

How? The only way RDF is capable of that is property based 
equivalence. There are strong philisphical arguments for and against 
it. If your RDF graph around that URI and my RDF graph around that 
URI intersect sufficiently, we're /probably/ talking about the same 
thing. It would require thresholding which leads you straight to 
probabilities. Which could be treated as preprocessing step for 
distributing an interpretation to an RDF graph. But the whole 
argument for using URIs in RDF in some people's eyes is that they 
/uniquely/ identify - there is no intepretative step because the web 
architecture deems that a URI has one and only Resource. Ever.

The point is that if we have to /calculate/ a URI's denotation to 
get something interesting done, RDF (and the Web Arch) had better 
acknowledge this.

> Clearly, a resource whose identification is 
> muddified or inconsistent is less useful, and makes the Web less useful.

Only in a binary web. In a probabilistic web, it's less of an issue.

Bill de hÓra
Received on Thursday, 23 January 2003 07:39:31 GMT

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