Hi Leo... (01)
Wow. That was a long reply. Rather than respond to all of it in
detail, allow me to compress your remarks. The fault lies with me if
I've misinterpreted anything you meant. (02)
> LEO: One distinction between entity-relation (or extended
> entity-relation) and UML on the one hand and RDF and OWL on the other
> is that the latter are primarily logics and have a defined formal
> semantics. (03)
Granted - there is a semantics to E-R and UML but they are very
weak. That wasn't what I was getting at, however. Let me put my
reply in the form of a question which I would like the UOS to address: (04)
(1) Is there a difference between a formally-expressed logical theory
and an "ontology"?
(2) If you answered YES to (1), then what is that difference?
(3) If you answered NO to (1), then why is this situation any better
for integration than the current state of data models, other than the
fact that once you posit some correspondences between models, the
logic helps you identify logical inconsistencies? (05)
> LEO: Data models primarily focus on "local" semantics, not "real
> world"
> semantics, i.e., the very narrow view from a need to organize data for
> specific purposes and applications in a given part of an organization. (06)
This is true. The job of a data model (as conventionally applied) is
to provide persistence support to applications. Of course there has
been a tremendous amount of work, dating back to the 70's (I'm
thinking of Bill Kent's "Data and Reality") that argue that data
models, too, need to pay attention to the "real world". Is the only
thing new with "ontologies" that they bring some extra logical muscle
to achieving this attention-paying on a larger scale? (07)
> LEO: I don't see any solution for semantic interoperability/
> integration
> that excludes the use of an upper ontology (or a lattice of theories,
> if you will, some of which are upper theories). (08)
As usual, I agree with you. However, if one counts up the projects
(and here I'm talking about *real* non-academic projects) that use an
upper level ontology to effect, that number is far outstripped by the
number of "beer ontologies" "wine ontologies", etc, that can be
easily demonstrated to be as rigid and non-extensible as data models. (09)
If the purpose of the UOS is to achieve some kind of grand
unification of existing upper levels, I think we're shooting at the
wrong target. That's an interesting project, but I don't think,
given the relatively sparse use of ULO in general, that it's the most
pressing project for those who care about ontology vs logic or data
modeling. There's no or little disagreement among this crowd that
ULO makes sense for lots of reasons. (010)
The real target, IMHO, is the view that so-called "domain
ontologies", or domain-specific "upper levels" using formal logics
constitute ontology at all. (011)
.bill (012)
Bill Andersen (andersen@xxxxxxxxxxxxxxxxx)
Chief Scientist
Ontology Works, Inc. (www.ontologyworks.com)
3600 O'Donnell Street, Suite 600
Baltimore, MD 21224
Office: 410-675-1201
Cell: 443-858-6444 (013)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/uos-convene/
To Post: mailto:uos-convene@xxxxxxxxxxxxxxxx
Community Portal: http://ontolog.cim3.net/
Shared Files: http://ontolog.cim3.net/file/work/UpperOntologySummit/uos-convene/
Community Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UpperOntologySummit (014)
|