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[OPEN] Guideline for when standard definitions are inadequate (was philosophy of SWBPD (was Re: [OPEN] and/or [PORT] : a practical question))

From: Uschold, Michael F <michael.f.uschold@boeing.com>
Date: Mon, 29 Mar 2004 14:45:20 -0800
Message-ID: <823043AB1B52784D97754D186877B6CF04894E14@xch-nw-12.nw.nos.boeing.com>
To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>, "Jim Hendler" <hendler@cs.umd.edu>
Cc: "Christopher Welty" <welty@us.ibm.com>, "Bernard Vatant" <bernard.vatant@mondeca.com>, "Ian Horrocks" <horrocks@cs.man.ac.uk>, "SWBPD" <public-swbp-wg@w3.org>, <public-swbp-wg-request@w3.org>

There is no guarantee that after long careful thought, the dc:subject as currently defined will be adequate to the needs of someone doing very careful modeling of subject [class/part] hierarchies.  This raises a general concern: while we always want to use existing standard definitions when we can, sometimes there may be a need to differ. This results from the truth that "there will never be one true ontology" even in rather narrow domains, but rather different ontologies will serve different purposes.

It would be good if we could come up with some useful things to say about this situation.  Here is a draft candidate 'best practice" guideline for this case:

Try to use standard definitions where possible, if not, then try to pull out common pieces of both definitions, and make the relationship between them explicit. If that is not possible, then in clear natural language, articulate how the new definition relates to the standard one, as well as why the standard one was inadequate to your purposes.  If you think that there are serious problems with the standard one that warrants being upgraded, then make those recommendations to the appropriate body.


 -----Original Message-----
From: 	public-swbp-wg-request@w3.org [mailto:public-swbp-wg-request@w3.org]  On Behalf Of Jeremy Carroll
Sent:	Thursday, March 25, 2004 12:26 AM
To:	Jim Hendler
Cc:	Christopher Welty; Bernard Vatant; Ian Horrocks; SWBPD; public-swbp-wg-request@w3.org
Subject:	Re: ALL: philosophy of SWBPD (was Re: [OPEN] and/or [PORT] : a  practical  question)

> Well, "mismodelling their world" is not limited to classes as instances. 
> I find it rather dangerous to make such statements.  People use subclass 
> incorrectly, too, but that wasn't a reason to remove that axiom from OWL 
> DL.  People just mismodel their worlds, I hope we can offer some advice 
> on both how to do some of these things and how NOT to do it.

> See, it's this kind of converse that makes me nervous -- somehow the 
> idea that the people who prefer separating class from instance (as Ian 
> is quoted by Jeremy) are right and those who prefer to use metamodeling 
> (like Guus as quoted to WOWG. I don't have time to dig up the mail) are 
> somehow mismodeling.  This is nonsense -- 

I agree with both these points ... but that doesn't mean that any use of 
classes as instances is well-modelled, and at least in this specific case, 
remembering Ian's reservations, it seems to me that classes as instances is 
  misguided (when using dc:subject). I am well aware that many others in 
this group know much more about subject hierarchies and modelling than I 
do, but we shouldn't shy away from making judgements.

My concern was about the implied relationship between *dc:subject* and 
*rdf:type* both of which are already defined.
If, after thinking about it (which I haven't), I thought that metaclasses 
were an appropriate modelling tool for this case, I think I would need to 
use a new property instead of *dc:subject* in order to express its 
relationship to *rdf:type*.

On the 'philosophy of SWBPD' topic, I hope that Network Inference, and/or 
others coming from the DL camp will participate in this WG, since I think 
we will be less able to represent (and forge) the consensus of the 
community without input from that part of it. (Certainly I am an unlikely 
champion of that school of thought !)

Received on Monday, 29 March 2004 17:51:21 EST

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