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Re: Syntax vs Semantics vs XML Schema vs RDF Schema vs QNames vs URIs (was RE: Using urn:publicid: for namespaces)

From: <kevin@globalplatforms.com>
Date: Tue, 14 Aug 2001 15:43:00 -0400 (EDT)
To: pat hayes <phayes@ai.uwf.edu>
cc: Patrick.Stickler@nokia.com, www-rdf-logic@w3.org
Message-ID: <Pine.LNX.4.10.10108141540120.28351-100000@mars.globalplatforms.com>
Folks:

I am new to this forum; please let me ask the following question:

	What are the technical issues, specifically contradictions that
are causing you grief on this issue?

Just trying to help (as I duck under my desk ;-)

Best Regards,

Kevin


On Tue, 14 Aug 2001, pat hayes wrote:

> >
> >Well, I'm probably going to get grilled for this comment, but personally
> >I don't like anonymous nodes. After all, just what *is* an anonymous
> >node. Every application that I've seen that uses them has had to give
> >them some form of identity, and yet that identity is system dependent.
> 
> The NODE has an identity, but it doesnt have a label which denotes 
> anything. The easiest way to understand anonymous nodes is just like 
> existentially quantified variables in logic, ie they assert that 
> something exists (just like a name or a URI does) but they don't give 
> it a name (unlike a name or a URI). That is widely considered to be a 
> handy thing to be able to do, and it is well-defined and seems 
> harmless, so why not allow it?
> 
> >IMO, anonymous nodes were a hack to allow collection structures as Objects,
> >but yet collections (or rather ordered collections) in RDF do not work in
> >an context of multi-source syndication (nor do DAML collections either).
> >The proper way IMO to model collections is using an ontology of collection
> >relations and plain old triples with no anonymous nodes; but that's a
> >separate
> >discussion that I don't want to start here.
> 
> Nothing would be greatly changed if all anonymous nodes were made 
> non-anonymous, but there would be a lot of silly names cluttering up 
> things to no useful purpose.
> 
> 
> >Issues of completeness required by the closed world folks can be addressed
> >by assigning source or authority to statements so that one can selectively
> >filter those collection members defined in a particular source or by
> >a particular authority and "outsiders" cannot add to that "view" of the
> >collection. IMO, the RDF conceptual model should have no anonymous nodes.
> >Collections based on serialized, syntactic structures should have no
> >realization in the underlying conceptual model; but again, that's yet
> >another discussion ;-)
> 
> That is certainly another point of view about collections, but there 
> are other reasons for allowing anonymous nodes.
> 
> >I will concede that there *might* be valid and necessary uses for anonymous
> >nodes which I am not yet aware of, but irregardless I get the impression
> >(and I may very well be wrong, apologies in advance) that anonymous
> >nodes are the new, "hot", interesting thing in RDF/DAML and so folks are
> >predisposed to using them to solve every problem even when more
> >constrained, simplier, and better alternatives may be available.
> >
> >For those who are convinced that anonymous nodes are a good thing, please
> >think about the implementational burden and portability/interoperability
> >issues they may introduce.
> 
> What burdens and issues? .
> 
> Pat Hayes
> 
> ---------------------------------------------------------------------
> (650)859 6569 w
> (650)494 3973 h (until September)
> phayes@ai.uwf.edu 
> http://www.coginst.uwf.edu/~phayes
> 
Received on Tuesday, 14 August 2001 15:43:41 GMT

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