Re: Need pointer to namespace discussion (rdf vs rdfs)

Dan Brickley wrote:
> On Tue, 17 Sep 2002, Murray Spork wrote:
> 
[...]
> 
> 90% historical accident. The old 1997-1999 Model and Syntax RDF Working
> Group tried to avoid defining more than it needed to. It gave us the
> notion of rdf:type (since we had special case RDF/XML syntax for encoding
> info about types in XML Markup). It gave us notion of rdf:Property, since
> each arc-label in a graph is of rdf:type rdf:Property. But it left to the
> RDF Schema WG the work of fleshing out the type/class system, ie. the
> notion that rdf:Property is of rdf:type rdfs:Class, and that each thing
> that was an rdf:type of something was itself a thing of rdf:type
> rdfs:Class.  And that classes had subclass relations, etc etc. In this
> context, it fell to the RDFS WG to give a name to the class rdfs:Resource.
> 
> Sometimes it's easy to slip into looking for technical / engineering
> reasons for design features that are artifacts of the way these specs are
> produced. It is only natural for such pragmatic considerations to affect
> specs, though if things went too far alarm bells should probably ring...


Thanks Dan. Point taken re "historical accident".

The reason I ask is that I am trying to determine exactly what concepts 
are 'RDF concepts' and what are introduced only in RDFS.

For example - it appears to me that RDF defines the concept of resources 
being typed (with an rdf:type property) - but the concept of class is 
only introduced in RDFS. How is it possible to type Resources without 
the notion of Classes from which these resources are typed?

Sorry to go over what undoubtadly is old well-trodden ground - but my 
reasonably comprehensive searches have not turned anything up that 
explains this.

-- 
Murray Spork
Centre for Information Technology Innovation (CITI)
The Redcone Project
Queensland University of Technology, Brisbane, Australia
Phone: +61-7-3864-9488
Email: m.spork@qut.edu.au
Web: http://redcone.gbst.com/

Received on Monday, 16 September 2002 23:52:25 UTC