Thomas G. Habing
Mon, 30 Apr 2001 16:45:09 -0500
Eric Lease Morgan wrote:
> Thomas G. Habing <email@example.com> wrote:
> > 1) There is no authoritative RDF XSD available (that we've know of) such as
> > would be required to conform to OAI validation requirements (nor for that
> > matter are there authoritative and extensible DCQ or DCA XSDs presently
> > available, and the available OAI DC XSD might not be extensible enough --
> > see below). There is presently considerable debate within the RDF community
> > as to whether XSD is sufficient to describe RDF -- so you might be skating
> > on thin ice here. One of the problems is that the true, allowable content
> > model for a given RDF element really varies based RDF attribute values
> > (e.g., RDF:parseType) -- something that's difficult to represent rigorously
> > enough in XSD.
> I'm a little bit out of my element here. What is XSD? A way to
> describe/initialize a namespace? ... Oh, it seems to be a schema.
Sorry for the jargon. XSD is indeed an XML Schema.
> > [Cool stuff deleted.]
> > The bottom-line is that there's a fair amount of work to be done to create
> > multi-namespace RDF files that can be validated using XSD as envisioned by
> > OAI. We'll be interested in any conclusions you reach. We'll pass along
> > what we learn as well.
> It sort of sounds to me that in order to create alternative metadata formats
> to be used in OAI one must create an XSD -- a schema, and RDF does not
> cleanly fit into schemas. Correct?
Yes and not entirely sure yet. OAI requires an XML Schema be available in
order to validate (check the correctness) of any alternate metadata
formats. But, after sending the previous message, I was able to find an XML
Schema for RDF (http://www.w3.org/2000/07/rdf.xsd), but I haven't had a
chance to test it yet. I suspect it will require some tweaking in order to
work with the latest XML Schema spec (a moving target). Plus, schemas for
any other namespaces that you intend to embed in the RDF will also have to
Anyway, this is something that we are actively pursuing, and are happy to
share once we figure out more ourselves.
Thomas G. Habing
Research Programmer, Digital Library Initiative
University of Illinois at Urbana-Champaign
052 Grainger Engineering Library, MC-274
firstname.lastname@example.org, (217) 244-7809
> Eric Lease Morgan
> NCSU Libraries
> OAI-implementers mailing list