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Re: Knowing where thing come from (was Re: Lang: owl:ontolgy )

From: Jonathan Borden <jonathan@openhealth.org>
Date: Fri, 20 Sep 2002 08:10:52 -0400
Message-ID: <001f01c2609e$c3e7e8d0$7c674544@ne.mediaone.net>
To: "Jeff Heflin" <heflin@cse.lehigh.edu>, "Christopher Welty" <welty@us.ibm.com>
Cc: <www-webont-wg@w3.org>

Jeff Heflin wrote:

>
> Just to refresh everyone's memory, this discussion began because of the
> proposals for handling imports that are based in XML/RDF syntactic
> inclusion. My whole point is that in every approach I've seen so far,
> this form of inclusion loses track of which statements come from which
> ontologies. In these cases, I no longer have the URLs of the documents;
> they were lost when one document was inserted into another. If all OWL
> parsers must perform this kind of inclusion, then people like me lose
> the ability to do the things I mentioned.
>
> Note, I was not arguing that we need to modify RDF or OWL in some
> radical way so that the model inherently includes source information
> (I'll save that battle for OWL 2.0 :-). I simply want to make sure we
> have solutions that don't prevent people who need source information
> from doing what they want.
>

From a practical point of view, this is all fine, except I'd like to see how
you _actually_ want to do it. You are teetering on, and perhaps have already
fallen deeply into the RDF "reification" rathole, and I'd prefer that we
simply don't go there.

RDF reification is the mechanism that has historically been proposed as a
way to attach metadata to _statements_, metadata such as source document,
and other assertions that might be made about a statement. You _could_
construct your RDF parsers to attach a "sourceURI" property to each reified
triple.

In a more perfect world I'd modify RDF to use quads rather than triples, and
the fourth member would be a URI that is used to "color" the triples. The
default case might be that the "color" of the triples in some document would
be the _baseURI_, but that's not something that's a part of RDF 1.x.

In summary, I understand what you want to do, and why you want to do it, but
its not something that can be done in a simple fashion at this time. I hope
that future versions of RDF will better handle this issue.

Jonathan
Received on Friday, 20 September 2002 08:28:36 GMT

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