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Re: A use case for anon nodes - action from telecon

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Tue, 17 Jul 2001 10:30:50 +0100
Message-ID: <3B5405CA.6F5E0329@hplb.hpl.hp.com>
To: Aaron Swartz <me@aaronsw.com>
CC: rdf core <w3c-rdfcore-wg@w3.org>
Aaron,

The thing to bear in mind about this submission is that these
were not my words.  They were the words (with some HP specific
stuff removed) of my colleagues who are using RDF in the manner
described.  This input is from real developers.

Aaron Swartz wrote:
> 
> On Monday, July 16, 2001, at 02:23  PM, Brian McBride wrote:
> 
> > (1) In the seller advert it would appear that the seller is
> > only advertising a
> > single specific (but under-specified) service, #anon12345 or
> > whatever, which
> > would be hard to distinguish from an actual service instance
> > like #service42.
> 
> Why would you want to distinguish between the two?

I think the idea here is that there will be URI's
denoting specific services.  My colleagues are 
interpretting a node with a URI to be denoting 
such a service.  It would be wrong to match a different
service.

When an anonymous node is specified, then no such constraint
exists.  Thus a processor would process these two instances
differently.

> And I see
> nothing about a URI that licenses you to assume that there is
> only such thing.

Oh we really do need this model theory don't we.  I tend to think
of a URI as identifying one thing, and one thing only, but that way
lies a philosphical debate on the nature of 'one'.  Shudder!


> 
> > (2) Similarly in the buyer advert instead of describing a
> > template, giving the
> > service a URI would make it appear that I am looking for a
> > specific service with
> > that URI.
> 
> Umm, aren't you? What's the difference? In both you're looking
> for something with these properties.

The difference is that when a URI is specified the assumption is
that someone, somewhere has defined a 'well known' name for this
service.

The essence of this issue seems to involve the idea that the
act of naming something in the internet is somehow, special.
That if a processor is told that something has URI ISBN-12345
or whatever, it had better not match that with anything that
it does not 'know' is named ISBN-12345.  On the other hand,
if a node is not named, then it can be matched with anything
that matches its properties.

I'm not sure that standard FOL captures this.  FOL is built
around a conceptual model where there can be many interpretations
for statements in the FOL.  But that is not the situation we
are in here.  We have one interpretation - its a mapping to 
the world out there.  Intuitively I feel that makes a difference.
That makes naming special.

Brian
Received on Tuesday, 17 July 2001 05:33:24 EDT

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