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

From: Bernard Vatant <bernard.vatant@mondeca.com>
Date: Fri, 30 Apr 2004 11:54:09 +0200
To: "Natasha Noy" <noy@SMI.Stanford.EDU>, "swbp" <public-swbp-wg@w3.org>
Message-ID: <GOEIKOOAMJONEFCANOKCMEDADPAA.bernard.vatant@mondeca.com>


Natasha and all

A suggestion for the use case scenario would be to give, instead of fictional examples,
reference to actual book publications, identified by their ISBN number, based e.g. on what
can be found at http://isbn.nu/ a very effective website from which pragmatic lessons for
this group can be learned IMO, and which provides what can be considered true cool SW
functionalities in its use of identifiers and dc metadata.

The search with "Lions" as subject at the above URL yields an impressive list of links,
the first hit being a permanent URL
somehow representing in the system the class of books of which subject is "Lions"
http://isbn.nu/sisbn/lions/
which yields as today 67 instances in the data base ... where the different flavors of
"subject" that have been discussed here can be found.

Note that each URL below is a permanent one build as simply as possible from the ISBN
number.
They use dc elements like author, subject, publisher etc, and what book vendors data bases
can retrieve from those (price, availability, delivery delays ...)

"The African Lion"
http://isbn.nu/089686328X
This one has for subject the Class Lion, and even a subclass of Lion actually.

"Baby Lion"
http://isbn.nu/1550417118
The subject is a specific instance, but considered as a "generic" one : a baby lion
similar to any baby lion

"Lenny the Lion"
http://isbn.nu/0893467995
The subject is I suppose a fictional instance ...

... etc

I think including those real examples in the document would make it more look like
real-world stuff, and show what added value an ontology could bring to the previous
resources, by hierarchical linking of e.g.
http://isbn.nu/sisbn/animals
http://isbn.nu/sisbn/mammals
http://isbn.nu/sisbn/cat%20family%20mammals
http://isbn.nu/sisbn/lions/

Bernard

Bernard Vatant
Senior Consultant
Knowledge Engineering
Mondeca - www.mondeca.com
bernard.vatant@mondeca.com


> -----Message d'origine-----
> De : public-swbp-wg-request@w3.org
> [mailto:public-swbp-wg-request@w3.org]De la part de Natasha Noy
> Envoye : mardi 27 avril 2004 21:57
> A : swbp
> Objet : [OEP] "Classes as values": summary of the discussion so far and
> second draft
>
>
>
> 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
>
Received on Friday, 30 April 2004 06:13:29 UTC

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