[wg11-owl] Re: Paper: Criticism of the STEP Application Module approach

[West, Matthew R SIPC-OFD/321]

Dear Colleagues,

I think Ed is right when he says:

> 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.

This would be how you would mine the valuable experience and engineering
knowledge contained in the various STEP APs into an ontology.

A move away from that mined ontology is something that should be subject
to change control and managed in the usual way by raising and resolving 
issues. I expect that making the onology more visible/explicit would make
the improvement process somewhat easier.


Regards

Matthew West
Reference Data Architecture and Standards Manager
Shell International Petroleum Company Limited
Shell Centre, London SE1 7NA, United Kingdom

Tel: +44 20 7934 4490 Mobile: +44 7796 336538
Email: matthew.west at shell.com
Internet: http://www.shell.com
http://www.matthew-west.org.uk/


> -----Original Message-----
> From: Ed Barkmeyer [mailto:edbark at nist.gov]
> Sent: 08 June 2005 17:10
> To: David Leal
> Cc: wg11-owl at steptools.com; Tore.R.Christiansen at dnv.com; 
> West, Matthew R
> SIPC-OFD/321
> Subject: Re: [wg11-owl] Re: Paper: Criticism of the STEP Application
> Module approach
> 
> 
> 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."
> 
> 
>