OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help



   Re: [xml-dev] Semantic Web permathread, iteration n+1 (was Re: [x ml-dev

[ Lists Home | Date Index | Thread Index ]

On Jun 3, 2004, at 9:32 AM, DuCharme, Bob (LNG-CHO) wrote:

>  the semantic web is something that
> will inspire great ideas that get implemented in a different, more 
> practical
> project?

For what it's worth, that's exactly the point I was trying to make in 
my response to Len.

Elliotte suggests that the essential subset to do real semantic 
integration will be XML+namespaces, and wonders what RDF brings to the 
table.  I'm a fairly hard-core RDF-skeptic myself, so I'm sympathetic.  
Nevertheless, to me it is OWL that provides the mojo powering my 
late-blooming interest in the semantic web stuff.  Of course, OWL *is* 
RDF, but it has a syntax that is more accessible and usable as XML.

For example, look at the ontologies under 
http://www.w3.org/2004/02/wsa/  (the OWL formalization of the W3C Web 
Services Architecture Note).  Maybe I'm not the best judge, but these 
seem fairly understandable to me, at least compared to other formal 
notations for this kind of thing.  It *was* useful to use OWL as the 
formalism because we (or actually the Carnegie-Mellon people who did 
the work!) could use the various OWL tools to check for undefined 
terms, multiple definitions of the same term, and generally to identify 
gaps and inconsistencies in the architecture.

In the day job, we have seen some real synergies between pure XML 
technologies such as XQuery and semantic technologies based on OWL.  I 
don't have the details, but I believe we can demonstrate how a huge 
ontology such as OpenCYC can be used more efficiently and effectively 
by a reasoner by storing the ontology in an XML database and 
selectively pulling out relevant subsets in chunks.  That works best if 
there is coherence between the XML syntactic structure of an ontology 
and the logical structure of the network of triples.  As I understand 
it, that is hard to pull off in raw RDF, but more effective in OWL.

Another point I'd make vis a vis what OWL adds over raw XML is its 
vastly richer notion of a relationship.  Of course, XML gets a lot of 
mileage with basically two built-in relationships,  "has-property" 
(that is, attributes on elements) and "contains" (subordinate 
elements).  The basic HTML hyperlink that Google exploits so well is of 
course another that is easily represented in XML.  I won't deny that 
one can get an awful lot of benefit from these, especially when it is a 
human consuming the information, but I'll suggest that OWL's much 
richer relationships (and the hierarchy of support for them in 
OWL-Lite, OWL-DL, etc.) prove their worth when dumb software is 
consuming the information.

Again, I am only at the periphery of this stuff so I can't explain or 
defend it in detail, but am just offering my impression that OWL allows 
one to leverage the undeniable strengths of XML in a way that RDF (or 
at least RDF-XML) does not.  I would be happy to be set straight by 
people who have a better grasp of all this!


News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS