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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: <Patrick.Stickler@nokia.com>
Date: Wed, 15 Aug 2001 13:24:24 +0300
Message-ID: <2BF0AD29BC31FE46B78877321144043114B4EF@trebe003.NOE.Nokia.com>
To: kevin@globalplatforms.com, phayes@ai.uwf.edu
Cc: www-rdf-logic@w3.org, www-rdf-interest@w3.org

See my other posting today titled 'Summary of the QName to URI 
Mapping Problem' for a brief discussion of the key issues.

Cheers,

Patrick


> -----Original Message-----
> From: ext kevin@globalplatforms.com [mailto:kevin@globalplatforms.com]
> Sent: 14 August, 2001 22:43
> To: pat hayes
> Cc: Stickler Patrick (NRC/Tampere); www-rdf-logic@w3.org
> Subject: Re: Syntax vs Semantics vs XML Schema vs RDF Schema vs QNames
> vs URIs (was RE: Using urn:publicid: for namespaces)
> 
> 
> 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 Wednesday, 15 August 2001 06:24:32 GMT

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