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Re: [OEP] "Classes as values": summary of the discussion so far and second draft

From: Deborah L. McGuinness <dlm@ksl.Stanford.EDU>
Date: Thu, 29 Apr 2004 10:57:47 -0700
Message-ID: <4091421B.7020308@ksl.stanford.edu>
To: Natasha Noy <noy@SMI.Stanford.EDU>
Cc: swbp <public-swbp-wg@w3.org>


thanks for the work and the update.
i have been in meetings and traveling for the last few days so have not 
gotten to look at this in detail.
one thing we might discuss briefly is if we are going to use the basic form:

problem description   (including background   and observations could fit 
in here as well)
use case example
abstracted solution
owl solution
implications
references

for the write ups and if so, make a small modification to accomodate this.

you also provided additional sections that we might want in all notes or 
might make optional but encourage.

Deborah

Natasha Noy wrote:

>
> As promised, you can find the second draft of the "classes as values"  
> note at
> http://lists.w3.org/Archives/Public/www-archive/2004Apr/att-0091/ 
> ClassesAsValues-v2.html
>
> Thanks a million to everyone for all the thoughtful feedback (and for  
> kind words along the way). I think the discussion is not over yet, I  
> tried to address some of the points that seemed less controversial 
> and  left some of the discussions (cf my replied to Alan [1] and Aldo 
> [2] up  in the air for the moment).
>
> In lieu of summary of the discussion, here is a list of main changes 
> in  this version.
>
> Running example: it was clear that my example of annotating images of  
> lions was a very bad one, since it wasn't clear whether a subject of 
> an  image (in the normal English interpretation of the term) is the  
> specific lion in the picture or lions in general. I was trying to  
> address the latter with the pattern and that's what I am trying to  
> stick to (other cases are for other patterns, I think). So, the 
> example  now is subjects of books, rather than images, which is a bit 
> less  ambiguous. A book about lions has the class or subject Lion as 
> its  subject, and a specific living breathing creature.
>
> Approach 2b is eliminated. It used rdfs:isDefinedBy  to link 
> instances  of Subject with the corresponding classes (such as 
> LionSubject and  Lion), but the solution was no different (but more 
> verbose) than  Approach 4, which used annotation property. The only 
> reason 2b was in  OWL DL was because rdfs:isDefinedBy was an 
> annotation property, since  it still had a class as its value
>
> Full solution in OWL and its different flavors. Deb pointed out in 
> her  template for patterns that each pattern should include a full 
> text of  the solution in OWL, which makes a lot of sense. I've added 
> that at the  end of each approach. Since I was mocking up all examples 
> in Protege  anyway, it was essentially no effort to add it in RDF/XML 
> syntax, N3,  and abstract syntax. So, take your pick :)
>
> Outstanding discussion and other issues: Alan and Aldo suggested  
> another approach which uses prototypes as values ([3], [4]). I think  
> with this more narrow scope of the example (subjects of books rather  
> than pictures), their solutions seem to address a somewhat different  
> problem. But I am not sure if we have reached closure on that.
>
> Also has also brought up the issue of ontological patterns vs 
> pragmatic  patterns [4]. I am not sure yet though is this is a use 
> case to  distinguish them explicitly here.
>
> From the public and private comments that I have received, it is 
> clear  that for each of the approaches, at least some people in the 
> group  consider them useful and would use them if they had to stay in 
> OWL DL  (and, for most, others consider them really bad and will not 
> use them  ever). So, I kept all of them for now.
>
> Am I forgetting some other outstanding issues?
>
> The rest are smaller changes that those looking for a higher-level  
> summary can easily ignore:
> - In approach 2, I made much more prominen the point that making  
> subjects individual instances of the corresponding classes will make 
> it  inconsistent with having real animals instances of the same 
> classes.  Also changed the summary for that approach
> - In approach 3, the rdf:type of subject individuals is now a single  
> class Subject (distinguishing this case from 2, and allowing actual  
> physical lions to be instances of the classes in the hierarchy)
> - In approach 1, saying that something is in OWL Full is not saying  
> much (after all,, all OWL DL ontologies are also in OWL Full). Rather  
> than saying that "This ontology is in OWL Full", it now says "This  
> ontology is in OWL Full, but not OWL DL".
> - In approach 4, added a diagram illustrating the approach.
> - Added a footnote anywhere allValuesFrom is used that in some cases  
> someValuesFrom would be more appropriate.
>
> Thanks a lot to everyone who has contributed to the discussion! And, 
> as  I pointed out earlier, I don't think we've reached closure on some 
> of  the issues, so, probably, there will be one more iteration.
>
> Natasha
>
> [1] http://lists.w3.org/Archives/Public/public-swbp-wg/2004Apr/0137.html
> [2] http://lists.w3.org/Archives/Public/public-swbp-wg/2004Apr/0153.html
> [3] http://lists.w3.org/Archives/Public/public-swbp-wg/2004Apr/0132.html
> [4] http://lists.w3.org/Archives/Public/public-swbp-wg/2004Apr/0149.html
>

-- 
 Deborah L. McGuinness 
 Associate Director Knowledge Systems Laboratory 
 Gates Computer Science Building, 2A Room 241 
 Stanford University, Stanford, CA 94305-9020 
 email: dlm@ksl.stanford.edu
 URL: http://ksl.stanford.edu/people/dlm
 (voice) 650 723 9770    (stanford fax) 650 725 5850   (computer fax)  801 705 0941
Received on Thursday, 29 April 2004 13:58:02 UTC

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