- From: Pat Hayes <phayes@ihmc.us>
- Date: Thu, 15 Apr 2004 16:54:00 -0500
- To: "Uschold, Michael F" <michael.f.uschold@boeing.com>
- Cc: <public-swbp-wg@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. Michael, WHAT the hell are you taking about? What 'existing standard definitions' ?? Even if they exist (I know of no such case, where there is a single existing standard definition of any concept in any ontology. RDFS and OWL disagree about the exact meaning of 'subclass' for example.), WHY would we want to use them? >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. Might be better to worry about what to say when the oceans freeze over. Pat >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. > >Mike > > > > -----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) > > >Chris: >> 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 !) > >Jeremy -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ihmc.us http://www.ihmc.us/users/phayes
Received on Thursday, 15 April 2004 17:54:02 UTC