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Re: SKOS Core review Re: issue: non-Literal "comment" properties Re: new draft of SKOS Core guide

From: Thomas Baker <thomas.baker@bi.fhg.de>
Date: Sun, 27 Feb 2005 19:08:38 +0100
To: Benjamin Nowack <bnowack@appmosphere.com>
Cc: "Miles, AJ (Alistair)" <A.J.Miles@rl.ac.uk>, public-esw-thes@w3.org
Message-ID: <20050227180837.GA2424@Octavius>

On Fri, Feb 25, 2005 at 06:28:15PM +0100, Benjamin Nowack wrote:
> >In the course of untangling these issues, we have ended
> >up in the DCMI Usage Board with a bias against building
> >implementation-related restrictions into the very definitions
> >of the vocabulary.  Limiting values to literals, for example,
> >can perhaps more appropriately be done in some sort of
> >application-profile construct rather than "once and for all"
> >in the canonical representation of the vocabulary.
..
> ...would you
> actually encourage vocab developers to invent hybrid
> properties (yep, by "hybrid" I meant plain rdf:Properties
> which don't constrain their range to either literals or
> non-literals)? I guess that'll be another "it depends"
> answer ;)

Benjamin,

I'm not familiar with the notion of hybrid properties in
the RDF context, so I may not be correctly understanding
your point...

The RDF schema in which http://purl.org/dc/elements/1.1/creator
(for example) is defined essentially says that Creator is
an RDF property, with a label, comment (definition), and
description.  In practice, RDF users have since 1997 been
using dc:creator for arcs that point either to a string or to
a node (i.e., resource) with its own properties (the latter
has sometimes been called a "structured value").

Does this make Creator a "hybrid" property?

It is true that differences between encoding styles have
created some difficulties -- see, for example, [1].  Are you
suggesting that the formal declaration of the terms in RDF
be more explicit in this regard?

Tom

P.S. I will be traveling and may not be able to follow up on
this thread until March 9...

[1] http://www.ukoln.ac.uk/metadata/dcmi/rdf-values/

-- 
Dr. Thomas Baker                        Thomas.Baker@izb.fraunhofer.de
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Personal email: thbaker79@alumni.amherst.edu
Received on Sunday, 27 February 2005 18:05:51 GMT

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