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

From: Natasha Noy <noy@SMI.Stanford.EDU>
Date: Sun, 2 May 2004 13:56:07 -0700
Message-Id: <2247D262-9C7B-11D8-8BD3-000A958B5C28@smi.stanford.edu>
Cc: "Uschold, Michael F" <michael.f.uschold@boeing.com>, "swbp" <public-swbp-wg@w3.org>
To: "Bernard Vatant" <bernard.vatant@mondeca.com>

Bernard, Mike,

Thanks for the pointer. I'll try to work some of Bernard's suggestions 
into the examples (plus the skos properties, if there is a consensus 
that this is the way to go). I am also a bit concerned that sending a 
reader to too many places just to illustrate an example may distract 
too much from the main point of a particular note. I'll try to find 
some reasonable compromise for the next version and we can go from 

It's indeed some effort, but probably worth it for readability of the 
final version.


On Apr 30, 2004, at 10:01 AM, Bernard Vatant wrote:

> Mike
>> An intriguing suggestion.
> Better "intriguing" that GOOD or BAD :))
>> I agree that our notes will be improved to the
>> extent that they use real/vs. fictional examples (modulo the sometimes
>> difficult challenge of finding real examples that are simple enough to
>> illustrate technical points in a clear way).
> The devil is in the (modulo) indeed. Real world is not simple, but is 
> not real world what
> this WG is about now?
> But in this very case, I think that e.g. "The African Lion" and "Denny 
> the Lion" are
> simple enough at a decent level of semantic granularity, IOW if we 
> don't make them too
> difficult to grasp by looking too closely at them.
>> Hopefully adding this would not be an undue additional burden on
>> Natasha, who has put in an enormous effort so far.
> Sure.
>> Mike
>> -----Original Message-----
>> From: Bernard Vatant [mailto:bernard.vatant@mondeca.com]
>> Sent: Friday, April 30, 2004 2:54 AM
>> To: Natasha Noy; swbp
>> Subject: RE: [OEP] "Classes as values": summary of the discussion so 
>> far
>> and second draft
>> 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 Sunday, 2 May 2004 16:56:08 UTC

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