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RE: comment on proposed policies for vocabularies

From: Miles, AJ \(Alistair\) <A.J.Miles@rl.ac.uk>
Date: Tue, 22 Nov 2005 12:02:48 -0000
Message-ID: <677CE4DD24B12C4B9FA138534E29FB1D98516E@exchange11.fed.cclrc.ac.uk>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, <public-swbp-wg@w3.org>

Hi Peter,

Thanks alot for this feedback, much appreciated.

> I just read http://isegserv.itd.rl.ac.uk/VM/http-examples/ 
> and I have a number
> of concerns.

Note revised draft at:

http://www.w3.org/2001/sw/BestPractices/VM/http-examples/2005-11-18/

... with revised language for the 'requirements'.

> These concerns mainly center around whether it is generally 
> possible to, "[f]or
> each HTTP URI denoting an RDFS/OWL class, property or 
> individual" there is a
> general notion of "a set of RDF statements constituting the 
> definitive RDF
> description of that class, property or individual".
> 
> First, some simple concerns.  Shouldn't it be an RDFS 
> description, at least?
> How can one distinguish between (non-OWL DL) RDFS classes, 
> properties, and
> individuals to determine just what to return?
> 
> Second, an OWL class, property, or individual should have an 
> OWL description
> instead of an RDF(S) description.  (Unless, of course, you 
> really mean to get a
> projection of an OWL description onto RDF(S).) 

I think this is a question of finding the right language.

By 'RDF description' of some thing I meant: a set of RDF statements 'about' (i.e. 'describing') that thing.  This was not meant to exclude RDF statements using RDFS properties/classes, or the RDF projection of an 'OWL description'.  Note also that this is not in my mind necessarily restricted to only RDF statements for which the thing in question is in the subject position, but more a set of statements for which the thing in question is the focus.

Any suggestion for how we could improve language here?
  
> Third, there could be several "definitive" descriptions.  I 
> might have one; you
> might have one; George W. Bush might have one.  What makes my or your
> description more definitive than the one used by George W. 
> Bush?  I don't see
> how this potential multiplicity can be resolved.

I think this is also a question of finding the right language. In conversation at ISWC2005 I remember you saying that it is reasonable for there to be a 'core' description for a class or property ... can you expand on this notion? 

I had always assumed that, to be able to access this 'core' description of a class/property by dereferencing the URI of that class/property was a (the?) fundamental principle of the architecture of the semantic web. TimBL seemed to reiterate that quite firmly in his keynote at ISWC2005. Do you agree with this? 
 
> Fourth, is there any way to limit what is in the "definitive" 
> description?
> To take an extreme viewpoint, *every* use of dc:author would 
> be part of its
> "definitive" description.

Again, if you could expand on a notion of a 'core' description, I think that would be helpful here.

> I have similar concerns with "... the most relevant item of 
> human-readable HTML
> content documentation for that class, property or 
> individual".  This is making
> a *very* strong statement that relevance can be determined 
> for each particular
> request.  How can a piece of software know what I consider to 
> be most relevant?

This was a purely pragmatic requirement. I.e. if I 'go' to the URI of a property using my web browser, it's usually more convenient if I end up looking at a description of that property, rather than the vocabulary/ontology as a whole or something else. This might mean scanning to the most relevant fragment of an html doc, or going to the right page in a linked set of docs.

> Note that I am *not* saying that there is nothing that can or 
> should be done
> along these lines.  It is just that the desiderata in the 
> document are, in my
> opinion, impossible to satisfy.

What do you think the desiderata should be? Are we generally barking up the right tree, or have we got something fundamentally wrong? Is it a question of finding the right language? If so, any suggestions?

Cheers,

Alistair.
Received on Tuesday, 22 November 2005 12:03:02 GMT

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