[OEP,ALL] Potential topics for OEP notes

Here are some suggestions for the topics of future OEP notes for "ontology 
patterns".  I want to get some feedback both from the task force and the 
WG in general regarding other topics.  This is something of a synthesis of 
stuff that is needed, and stuff that we think people can do.  Please make 
this an agenda item for next week's telecon.  We hope to have something 
more concrete by the f2f, this is just intended to get people thinking:

The partOf relation.  There really isn't that much that can be "said" in 
OWL (and therefore less in RDF) regarding the typical axiomatizations of 
partOf, but knowing the different kinds of partOf relations and what they 
are supposed to mean would be useful.  I'm hoping that some subset of 
Nicola, Alan, and I can take the lead on this one, but I also see the need 
for a couple of notes here, so I think this needs further discussion.  For 
example Deborah expressed interest in a simpler note (less ambitious but 
quicker turnaround) on geographical containment.

Units and measures.  There has been some work on this, including in Cyc, 
Tom Gruber's ontology in Ontolingua, and Helena Sofia-Pinto did a nice one 
for the old SUO effort.  Evan was interested in this and it certainly 
makes sense to have someone at NIST do it.

Subjects.  The notion of what a subject "is" and what the "subjectOf" 
relation means can be quite confusing.  I have done a lot of work on this 
and am willing to take this one on, however I will want to do one at a 
time.

Time.  Jerry Hobbs has done a very thorough job putting together a 
consensus ontology of time based on a lot of existing time ontologies, 
most of which draw from the Allen calculus.  The ontology is expressed in 
FOL (KIF), but there are (necessarily simplified) DAML+OIL and OWL 
("OWL-Time") versions  available.  Jerry has expressed interest in seeing 
this as a W3C note.

Fluents.  Closely tied to the notion of time is being able to say that a 
binary property "holds" for a time. e.g. one may want to say that "Chris 
is a member of the W3C from Sept, 2004 - Sept 2005".  A property like 
memberOf is a fluent because it can be said to hold at a time (this is not 
strictly a correct definition, but it will suffice).  While OWL-Time let's 
you represent a time interval like "Sept, 2004-Sept, 2005", it remains 
neutral wrt what happens at or during such a time interval.  The typical 
move in FOL is to use a function or add an argument to the predicate, e.g. 
memberOf(Chris, W3C, time-interval-1), however clearly we can't do that in 
OWL or RDF, since we are limited to binary predicates.  One solution is to 
go for full reification of fluents, as in the exsiting not on n-ary 
relations, however there are some other choices.  I'm hoping I can get Pat 
Hayes and Richard Fikes to work with me on this one.

On the side of "ontology engineering":

Ontology 101 tutorial specifically for OWL/RDF.

I think a note to help orient people on the role OWL and RDF in semantic 
integration is critical, I get pinged on that regularly.  I lot of people 
think OWL is the silver bullet for semantic integration (I suggested at 
ISWC last year that semantic integration is a mountain, not a werewolf, 
and OWL is, at best, a small silver chisel). There was just a Dagstuhl 
symposium on this subject in general (i.e. not specific to OWL), and 
special issues of AI Magazine and Sigmod record coming out as well.  I 
hope Natasha and/or MikeU will take the lead on such a note.

People who know what "ontology" and "semantics" actually mean (in the much 
larger world outside of computer science), often ask why the two have 
become nearly synonymous on the semantic web.  Personally, I think its a 
fair question and a short note on why we're so confused would be 
worthwhile.  Maybe this goes in another task force (wasn't there a clean 
up the mess we've made task force?)

We're open to other suggestions.

-Chris (OEP co-co)

Dr. Christopher A. Welty, Knowledge Structures Group
IBM Watson Research Center, 19 Skyline Dr., Hawthorne, NY  10532     USA   
 
Voice: +1 914.784.7055,  IBM T/L: 863.7055, Fax: +1 914.784.7455
Email: welty@watson.ibm.com, Web: 
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