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Re: Subclass of Thing/Resource

From: Marja-Riitta Koivunen <marja@w3.org>
Date: Tue, 07 Mar 2000 00:18:25 -0500
Message-Id: <3.0.5.32.20000307001825.00f33890@localhost>
To: Dan Brickley <Daniel.Brickley@bristol.ac.uk>, Guha <guha@epinions-inc.com>
Cc: www-rdf-interest <www-rdf-interest@w3.org>
At 12:02 AM 3/4/00 +0000, Dan Brickley wrote:
>On Fri, 3 Mar 2000, Guha wrote:
>
>> Tim,
>> 
>>  I think many of these questions center around
>> precisely defining what an RDF Resource Identifier
>> is supposed to be.
>> 
>>    I agree that we need to distinguish between RDF
>> Resource identifiers and URIs. A URI is a pretty formal object
>> (protocol + host + opaque string) whose definition pretty
>> concretely  constrains what can have a URI. By
>> this definition, people, places, etc. cannot have URIs.
>
>Sorry Guha, you're quite definitively wrong on this last claim. I agree
>that we need more clarifications in this area, but the URI spec (as
referenced 
>from RDF Model and Syntax) is very clear on this point:
>
>
>>From http://www.isi.edu/in-notes/rfc2396.txt
>
>[begin excerpt]
>
>Network Working Group                                     T. Berners-Lee
>Request for Comments: 2396                                       MIT/LCS
>Updates: 1808, 1738                                          R. Fielding
>Category: Standards Track                                    U.C. Irvine
>                                                             L. Masinter
>                                                       Xerox Corporation
>                                                             August 1998
>           Uniform Resource Identifiers (URI): Generic Syntax
>
>[...]
>
>	Abstract   
>	   A Uniform Resource Identifier (URI) is a compact string of characters
>	   for identifying an abstract or physical resource.  This document
>	   defines the generic syntax of URI, including both absolute and
>	   relative forms, and guidelines for their use; it revises and replaces
>	   the generic definitions in RFC 1738 and RFC 1808.
>
>[...]
>      Resource         
> 	 A resource can be anything that has identity.  Familiar
>         examples include an electronic document, an image, a service
>         (e.g., "today's weather report for Los Angeles"), and a
>         collection of other resources.  Not all resources are network
>         "retrievable"; e.g., human beings, corporations, and bound
>         books in a library can also be considered resources.
>
>	 The resource is the conceptual mapping to an entity or set of
>         entities, not necessarily the entity which corresponds to that
>         mapping at any particular instance in time.  Thus, a resource
>         can remain constant even when its content---the entities to
>         which it currently corresponds---changes over time, provided
>         that the conceptual mapping is not changed in the process.
>
>[end excerpt]
>
>> 
>>  On the other hand, it would be very convenient to have
>> a unique canonical identifier for refering to the one TimBL
>> or one RalphSwick. In my reading, this is what the RDF
>> Resource ID is. Everything (including literals, URIs, ...) could
>> potentially have one of these.
>
>Maybe, though I don't see any scenario whereby we'll end up with unique
>canonical identifiers for persons. Social/political/privacy issues
>aside, it's just too hard to do. That said, mailboxes, national
>insurance numbers etc allow us to say things like 'the person whose
>util:personalMailbox is mailto:guha@epinions...', uniquely picking out a
>flesh and blood person without (a) giving them a URI, (b) making a
>category mistake and conflating them with their mailbox URI.
>
Isn't social security number just that? Maybe in the future they will use a
 URI instead of a number. Another thing is then do the users want to use it
because of privacy issues.

Marja
Received on Tuesday, 7 March 2000 00:23:09 GMT

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