[OAI-implementers] XML records and RDF

Leo Przybylski leop@engr.arizona.edu
Thu, 7 Mar 2002 07:58:00 -0700


Hello,

I'm not an RDF expert either, but I do consider myself to have well 
researched DC and RDF together. I have also been looking for a way to extend 
DC.

RDF is very extensible. Their Schema can easily be added to using RDF. 
Unfortunately, RDF isn't just XML. It's almost a parallel data model to XML. 
The RDF community has developed their own processor for it. It has its own 
Schema model.

The subject of RDF and DC gets into "web semantics". You may have already 
read this, but I'll send it anyway: 
http://talad.sis.pitt.edu/marut/soa/SemanticInteroperability.pdf

Personally, I am leaning (though still undecided) not to go with RDF. My 
concern is not with semantics, I don't want to run the risk that someone else 
is not using RDF, and I don't want to chase down an API for using an RDF 
processor. 

You may have noticed that the DC RDF Schema isn't all RDF. That's right. They 
have a plain old XML schema. It looks like they're encapsulating their XML 
inside an RDF description. (Correct me if I'm wrong on this. Again, I'm not 
an expert). If you really want to extend DC, I've found you can easily do it 
right through the XML Schema into anything you want (doesn't have to be RDF 
at all).

Hope this helps,
-Leo

On Wednesday 06 March 2002 20:16, Alan Kent wrote:
> I was looking at the feasibility of putting up a collection of
> records using a scheme which is an extension of Dublin Core. However,
> they have encoded the records using RDF rather than the simpler
> OAI schema as used for Dublin Core records. (ie: lots of
> <rdf:description> and <rdf:value> elements all over the place.)
>
> The DC records included in appendex of the OAI 1.1 spec however
> does not use RDF.
>
> Just wondering if there was any reason for me not to return my
> records using the RDF based schema? I could try and convert them
> to the OAI DC schema as well (so available in both formats).
> Just wondering if there was any wisdom here. (Eg: "we chose not
> to use RDF based DC XML because...").
>
> I am not an RDF expert by the way, so don't understand all the
> subtlties that may be involved.
>
> Alan