[wg11-owl] Re: Paper: Criticism of the STEP Application Module
approach
Ed Barkmeyer
edbark at nist.gov
Wed Jun 8 12:09:40 EDT 2005
David Leal wrote:
> The paper is attached.
Thanks for that.
> Unfortunately I do believe that - the negative assessment is true in many
> cases. The STEP methodology can fix-up ill-defined concepts by specific
> usages within an AP, but as soon as the concepts are converted into an
> ontology, the failings are exposed and need to be fixed.
Exactly. Moreover, we have then the opportunity to determine whether
the "interpretation" in the AP, which should be a consistent
micro-theory, is in fact consistent with the "fixed" general interpretation.
> The creation of an
> 'ontology' of ill-defined concepts is a complete waste of time.
I agree fully. But we need to be careful to distinguish "well-defined
very general concepts", like much of the SUMO stuff, from "ill-defined
concepts". It is my perception that SC4 was trying to do the former,
but, as a body, lacked the linguistic/semantic discipline to do that
well (as evidenced by bad definitions and some misguided half-educated
dicta from the "Quality committee"). I have no objection to converting
bad definitions to good ones, so long as the intent of those definitions
does not change. I do object to converting intentionally general
definitions to narrower ones, even when the latter is "what we should
have meant".
Further, in making ontologies from SC4 models, there is nothing sacred
about IRM concepts. IRM concepts, AIC concepts, module concepts and AP
concepts are all Given. The object is to fashion consistent ontologies
from the set of Givens. In the long run, what counts is that we have
good ontologies for the AP, AIC, and module models. If consistency in
that universe can be attained by using the apparent ontology for the IRM
concepts, well and good. But if it can't, valueless IRM classes and
properties can be discarded in favor of valuable (and recurring) AP,
AIC, and module interpretations.
The argument about the term "product", for example, is that it is
intentionally broader than was necessary, and that it merges (the "in"
word is "confabulates") two importantly different concepts - a thing and
the design for the thing. We can't "fix" either of those errors in Part
41 without risking inconsistency with some AP interpretation.
But the "SC4 ontology" need not use "product" from Part 41 at all, if
there are two inconsistent interpretations that are used in APs. We
state the two AP definitions, prove the inconsistency, and discard the
Part 41 term, in favor of the two AP terms or two terms, each being
"product" qualified by some word that distinguishes the AP definitions.
My concern is that the "SC4 ontology" match, not rework or redefine, the
SC4 models. It does not have to "match" the broken parts of the SC4
architecture.
-Ed
--
Edward J. Barkmeyer Email: edbark at nist.gov
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8264 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8264 FAX: +1 301-975-4694
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority."
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