W3C home > Mailing lists > Public > www-webont-wg@w3.org > May 2002

Re: update to the compliance document

From: Jeff Heflin <heflin@cse.lehigh.edu>
Date: Fri, 31 May 2002 16:55:41 -0400
Message-ID: <3CF7E34D.619A52DC@cse.lehigh.edu>
To: WebOnt <www-webont-wg@w3.org>

Jim Hendler wrote:
> Jeff - two points
>   1) As I said in my report from WWW, it appears there is a large and
> growing group of users of DAML who are using what might be called
> "thesaurus" systems -- they publish a vocabulary, but the vocabulary
> was created in a different (usualyy proprietary) system.  These users
> use something similar to what was in SHOE or RDFS, but they also need
> to express some property restrictions - in particular, it is RDFS +
> unambiguous/unique + sometimes real cardinality.  I would venture
> that this is far and away the largest group of current users, and a
> group who OWL Core should support.  These are not group 2
> (description logic) users, and these are people publishing a lot of
> DAML (example, US National Cancer Institute will publish a 40,000
> term thesaurus updated monthly in D+O subset of this kind) - any
> attempts we make to guess what people will do should certainly
> include this group.

I was not aware of this group (unfortunately I had to miss WWW), but
agree that we should add it to the list. Without knowing the specifics
of these thesaurus systems, I can't say how for how sure it fits into
the picture, but I imagine that they would not be able to claim level-1
compatability (as currently defined). In particular, I doubt their
systems can reason with existential local range restrictions and I would
bet that if they use universal local range and local cardinality
restrictions, that they use them as constraints, as opposed to axioms
for drawing inferences (as implied by the semantics of DAML+OIL). This
could be a case to further reduce level-1, or maybe we throw thesaurus
systems in with the "database crowd."

>    2) I'm not sure what you mean by "almost back at full language" so
> I decided to do the experiment we ran at the f2f -- I took all the
> D+O language features and mapped them against Deb's level 1, and then
> look at the remaining.  I believe the following are NOT in level 1:
> complementOf
> disjointUnionOf
> disjointWith
> hasValue
> intersectionOf
> oneOf
> onProperty
> unionOf
> (which is a significant group).

I don't believe disjointUnionOf is in consideration for the full
language, and onProperty is just an artifact the RDF serialization of
DAML (it is required for all restrictions). Still, that leaves us with:


The first three (complementOf, interectionOf and unionOf) are what I
meant by boolean combinations. Still, that leaves three other features I
didn't realize were left out. I would argue that hasValue and oneOf are
likely to be as widely or more widely used than existential local range
restrictions (hasClass). That certainly appears to be the current case
for DAML+OIL ontologies (see http://www.daml.org/ontologies/features).
So, I would argue if you add local range restrictions, then you should
also add these two as well. Once you do that, then you are getting
pretty close to the full language again.

> I also suspect that not all of these would go in core - or might be
> otherwise simplified, depending on how our issue re: datatypes
> finally works out:
> Datatype
> DatatypeProperty
> DatatypeRestriction
> Datatype value

If datatypes are done in a similar way, then I expect all of these (or
equivalents) would be in the core.

> In addition, we haven't discussed whether the "extralogical" things
> we want would also go in core.  I expect they would, so I do not
> include:
> imports
> versionInfo

I would have a major objection if these did not go into the core.

> I believe the big difference between Core as expressed by Deb and
> Core as proposed at f2f if that at the f2f, we assumed that those 8
> things not currently in core would be in core for "named" classes.
> Deb's document takes them out of core completely.  That seems to me
> to be a very big difference.
>   -JH
> --
> Professor James Hendler                           hendler@cs.umd.edu
> Director, Semantic Web and Agent Technologies     301-405-2696
> Maryland Information and Network Dynamics Lab.    301-405-6707 (Fax)
> Univ of Maryland, College Park, MD 20742          240-731-3822 (Cell)
> http://www.cs.umd.edu/users/hendler
Received on Friday, 31 May 2002 16:56:26 UTC

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