[wg11-owl] Re: Paper: Criticism of the STEPApplicationModule approach

[Nigel Shaw]

David

In the spirit of the well-defined general concepts discussed below, would
you please define "it" as used in "Let's do it."

Thanks

	Nigel

--
Nigel Shaw
Managing Director, Eurostep Limited
Cwttir Lane, St. Asaph, LL17 0LQ, UK
Tel + 44 1745 582008 Mobile +44 7785 386913
nigel.shaw at eurostep.com www.eurostep.com

-----Original Message-----
From: wg11-owl-bounces at steptools.com [mailto:wg11-owl-bounces at steptools.com]
On Behalf Of David Leal
Sent: 10 June 2005 09:21
To: wg11-owl at steptools.com
Cc: matthew.west at shell.com; Tore.R.Christiansen at dnv.com
Subject: Re: [wg11-owl] Re: Paper: Criticism of the STEPApplicationModule
approach


Dear Ed,

I agree.  Let's do it.

Ray and I had a go with part 42, which is probably the best defined of the
IRs and one which is not re-defined by the APs. Even so there are a few
unexpected results.

Best regards,
David

At 12:09 08/06/2005 -0400, you wrote:
>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."
>
>

============================================================
David Leal
CAESAR Systems Limited
29 Somertrees Avenue
Lee London SE12 0BS
Tel:      +44 (0)20 8857 1095
e-mail:   david.leal at caesarsystems.co.uk
web site: http://www.caesarsystems.co.uk
============================================================

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