Dear John, (01)
> JFS>> But the more ontologies you add to the hierarchy, the easier
> >> it becomes to mix and match modules to create new ontologies.
> MW> Not if they use different upper ontologies. You can only mix
> > and match ontologies that are consistent...
> I agree that you can't mix inconsistent ontologies, but it's not
> necessary to have a single upper level. The beauty of the lattice
> is that it can support an open-ended number of different R & D
> projects at the upper, lower, and middle levels simultaneously.
[MW] Indeed, though as I mentioned elsewhere, the number of upper ontologies
that are likely to emerge are quite small, if they are restricted to
ontological commitments and core relations and categories. This is just
because there are a limited number of such commitments, and not all
combinations are coherent. (02)
> MW> ... and they are only consistent if they use the same upper
> > ontology (ontological commitments, core relations an categories).
> That is false. Two low-level theories that have nothing in common
> are *guaranteed* to be consistent. (03)
[MW] That is true but not useful. If there is no point of contact between
two ontologies, there is nothing to integrate. (04)
> Similarly, two very general
> theories can have an open-ended number of specializations, some
> of which are consistent and some of which are inconsistent.
> The lattice can support all of those combinations simultaneously. (05)
[MW] I agree, and that is more useful. (06)
> PC> You do need an FO if multiple independently developed
> > domain ontologies want to share data and interoperate
> > automatically.
> That is false. You can make independently developed systems
> with inconsistent or even undefined upper levels interoperate.
> OntologyWorks does that all the time. (07)
[MW] That is true. (08)
> The key point is that
> you should *never* try to merge two total ontologies. (09)
[MW] That is false. It depends what you are trying to do. For example, if
you are replacing several small systems with a single large system it would
be very sensible to integrate the ontologies from the small systems in
developing the new system. (010)
> you only need to extract the parts that are necessary for the
> task(s) on which interoperability is required. (011)
[MW] I would rather say that is the minimum you should do. In practice I
have found this can be significantly sub-optimal when that are multiple such
projects to be executed (as there usually are).
> PC> ... there has been much fuzziness about what should or should
> > not be in an "upper ontology". That is one of the reasons why
> > I have suggested that focusing on the semantic primitives is
> > a way of putting some boundary on the task.
> There's a better solution: remove *all* boundaries by supporting
> a framework that allows an open-ended variety of upper levels. (012)
[MW] Your missing the point. Pat is talking about what I would be inclined
to call a defining ontology. The idea being that it contains sufficient
concepts that all other possible concepts could be defined in terms of them.
That clearly goes beyond what I have been describing as an upper ontology. I
think the distinction is useful.
> MW> Well contracts and agreements and organizations are found
> > in industry as well, but generally not criminal law.
> Have you heard about Bernie Madoff? He's now in jail. (013)
[MW] By which I meant that the trading systems do not incorporate criminal
law (but will include at least bits of contract law). But that is not enough
to make something "upper" in my terms, because there are no ontological
commitments involved. As I said before, being important is not enough to be
> MW> I would see law itself as a domain and possibly many other
> > social concepts as domains, just as engineering is.
> There was a large project in Germany that tried to implement
> and reason about an ontology for German law for motor vehicles.
> They thought that would be a small, well-defined domain. But
> they discovered that almost every case involved vehicles that
> interacted with people, objects, and situations in every
> imaginable domain. (014)
[MW] I'm not surprised. But it still does not make it upper in my terms. (015)
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