Dear John, (01)
> MW
> > ... both you and Doug completely missed the point that we were talking
> > about methodologies for INTEGRATING (or conceptual) ontologies, not
> > reasoning ontologies.
>
> First of all, you cannot separate concepts from reasoning.
> But that is not the source of the disagreement.
>
> I believe that our disagreement arises over the distinction between a
> descriptive definition and a proscriptive or normative definition.
> In your work at Shell, you were defining standards for integrating the
> engineering designs at a single company. For that purpose, you needed to
> specify normative standards. (02)
MW: Not at all. We were defining standards for use throughout the supply
chain. For that purpose we need to specify normative standards. This is a
common requirement in other industries too. Mike Bennett for instance is
doing a similar thing for the Finance Industry, I know of groups doing the
same thing in the Building Industry etc. Etc.
>
> I recognize the importance of specifying engineering standards, especially
> since I have participated in ISO standards groups.
> But we also need to design our systems to interoperate in a world of
people
> and systems over which we have no control. (03)
MW: Of course we do. That is what we have been doing, and you saying
otherwise does not make it so.
>
> MW
> > The whole purpose of an integrating ontology is to be able to leave
> > the legacy systems alone, but bring together their data in a uniform
> > environment so that data can be analysed across multiple applications.
>
> I believe that we should use the term 'normative' for any ontology that is
> designed to establish a standard for some domain.
>
> Since legacy systems run the world economy and they're not going away, we
must
> also relate the normative concepts to the descriptive concepts about a
wide
> range of systems whose design is outside our control. (04)
MW: It is the other way round. We need to relate the concepts in a wide
range of systems to the normative standards. That gives some interesting
requirements on those standards:
- The standard needs to be able to have any concept from those legacy
system mapped to it, which in turn means,
- The standard needs to be extensible, but stable (you don't want to have
to change what you have when you add something new - it's probably already
being used)
>
> MW
> > CYC is not an integrating ontology - granted it is very large, but it
> > has an entirely different purpose.
>
> I agree that Cyc was primarily designed to be a descriptive ontology, but
it
> can also support microtheories of normative concepts for any purpose
anyone
> might need to specify.
>
> For example, Cyc can give underspecified definitions for time and space
that
> avoid any commitment to a 4D or a 3+1 D ontology. Then different
> microtheories could add axioms that complete the spec in one way or the
other. (05)
MW: Yes, but can it translate between them? Unless you have the means to
bring different ways of describing the same thing into a single
representation, you cannot bring together data from different sources. (06)
MW: On the contrary, for an integrating ontology, you only want one way to
say something, but you want it to be the most expressive way of saying it,
so that any other way can be expressed that way.
>
> JFS
> >> Avoid making detailed commitments in the top levels. Push any
> >> complex details or distinctions into the middle and lower levels.
>
> MW
> > Rubbish. You should make commitments at the appropriate level.
>
> I can't disagree with the sentence following the word 'rubbish'.
>
> But I had descriptive ontologies in mind. (07)
MW: We are not talking about descriptive ontologies in this session, so
anything about descriptive ontologies was off topic. (08)
> I believe that it is possible to
> communicate between systems that use different and even inconsistent
> ontologies or no explicit ontology of any kind. (09)
MW: Of course it is POSSIBLE, but it is also UNNECESSARILY EXPENSIVE unless
you only have 2 or 3 ontologies to ingtegrate, or you use an integrating
ontology to mediate between them.
>
> An underspecified descriptive ontology could be used for general
> communication. You could define your ontology as a stand-alone normative
> ontology. But for broader communication, a copy of it could be inserted
as a
> microtheory underneath a descriptive ontology. (010)
MW: That does not help.
>
> Communications between the systems are possible if the messages do not
require
> any of the details that cause conflicts. (011)
MW: That is even worse. You have to be able to translate between conflicting
representations, and bring the results into one environment, or you have not
actually managed to integrate anything. (012)
> I believe that our disagreements would vanish if we adopt the terms
> 'normative' and 'descriptive'. (013)
MW: Our disagreements would disappear if you discussed the topic at hand
instead of riding your hobby horses. We defined the terms we were using as
reasoning and integrating, we would appreciate it if you would use our
terms.
>
> I agree that an ontology used *only* for normative purposes can put design
> decisions (such as a 4D vs 3+1 D ontology) at the highest levels. But to
> support communication with outside systems (and interoperability depends
> critically on communication), it is necessary to use a very underspecified
> upper level. (014)
MW: It should not be underspecified. To under specify would risk poor
mapping into the ontology, the rules you define would prevent this. Poor
data quality would result. As I said before, it should be correctly
specified with axioms appearing at the right level, neither higher nor lower
than they properly belong.
>
> In summary, your normative ontology could be used with a descriptive
ontology
> such as Cyc by defining it as a Cyc microtheory in which the
underspecified
> terms in the upper level would become fully specified in the way that your
> ontology requires. (015)
MW: No. What you would need is a mapping between Cyc and your integrating
ontology so that different microtheories that covered the same area of the
integrating ontology were mapped to the same place in the integrating
ontology. This would bring all the ground facts in Cyc into a form where
they could be compared, and integrated with those from different sources. (016)
Regards (017)
Matthew West
Information Junction
Tel: +44 1489 880185
Mobile: +44 750 3385279
Skype: dr.matthew.west
matthew.west@xxxxxxxxxxxxxxxxxxxxxxxxx
http://www.informationjunction.co.uk/
http://www.matthew-west.org.uk/ (018)
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