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OWL and untamed RDF data

From: Graham Klyne <gk@ninebynine.org>
Date: Fri, 09 May 2003 23:40:03 +0100
Message-Id: <5.1.0.14.2.20030509232155.02613240@127.0.0.1>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>, w3c-rdfcore-wg@w3.org

Jeremy,

If I understand you correctly, this means that the world of "general RDF" 
and the world of "OWL reasoners" will only be able to operate with mostly 
disjoint data.  This seems to me to be completely at odds with the web and 
Semantic Web architectural directions.

But I don't understand the detailed technical issues sufficiently well.  In 
any case it seems to me that (if there is a problem here) the loser here is 
OWL, not RDF, in that it simply means that OWL will become an irrelevant 
backwater specification if it can't be used with the majority of "untamed" 
RDF.  The loss to RDF is that the hope for more robust reasoning 
capabilities is delayed until some other work is done.  (I, personally, am 
not convinced that the world is yet ready for a "standard" logical layer -- 
RDF (as a primarily descriptive language) is still very early in its 
life-cycle, and it's debatable if the world is yet ready for that, but I 
think it's not so far off.  I can imagine a range of useful applications 
developing in the relatively near-term based on a combination of RDF + 
CWM-like tools;  the more ambitious general reasoner and agent 
communication stuff still feels to me like research rather than standards 
material.)

So, while I'd be prepared to work jointly with someone about this if there 
really are technical problems, I really don't know enough to feel competent 
to make such a serious allegation against OWL on my sole initiative.

#g
--

At 22:12 09/05/2003 +0100, Jeremy Carroll wrote:

> > describe anything about which one wants to reason using OWL, then I think
> > there's potentially a serious architectural disconnect.
>
>As I understand it,
>
>
>An OWL DL or OWL Lite reasoner reads both the ontology data and the 
>instance data and interprets them with the OWL abstract syntax (which has 
>the the section called facts for such instance data:
>http://www.w3.org/TR/owl-semantics/syntax.html#2.2
>[[
>There are two kinds of facts in the OWL abstract syntax.
>
>
>The first kind of fact states information about a particular individual, in
>the form of classes that the individual belongs to plus properties and values
>of that individual.
>]]
>)
>
>All of these are subject to the bnode restrictions - although there are 
>subtle differences between those on the unnamed individuals and those on 
>the description and restriction nodes. I believe the WG endorsed my 
>comments on the unnamed individuals and not the description nodes - which 
>is fair enough.
>
>Graham, if you think you have an issue here that is not covered by the 
>comments Brian has sent, I would suggest you send a personal comment.
>
>Jeremy

-------------------
Graham Klyne
<GK@NineByNine.org>
PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E
Received on Friday, 9 May 2003 18:43:48 EDT

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