RE: OWL and Published Subjects

["Bernard Vatant" <bernard.vatant@mondeca.com>]

Jim

Right. I have no further specific concerns nor requirements that are not
adressed. Time permitting, I will push both to WebOnt and to PubSubj TC a
draft vocabulary for OWL-PSI.

Thanks for keeping interested in that matter.

Bernard

> -----Message d'origine-----
> De : public-webont-comments-request@w3.org
> [mailto:public-webont-comments-request@w3.org]De la part de Jim Hendler
> Envoye : vendredi 20 juin 2003 01:25
> A : Bernard Vatant; Public-Webont-Comments@W3. Org
> Objet : Re: OWL and Published Subjects
>
>
>
> At 5:36 PM +0200 5/6/03, Bernard Vatant wrote:
> >Please find below some comments about expected interoperability of OWL,
> >Topic Maps in general and Published Subjects in particular.
>
>
> Bernard - thanks for these comments - we are very pleased to learn
> that OWL meets the requirements for Published Subjects.  We believe
> that no changes to OWL are requested below, could you confirm that or
> let us know if you have concerns that we haven't addressed
>   -Jim H.
> p.s. Speaking for myself, not as a representative of the WG, I like
> the idea of some sort of PSI-in-OWL document, and would like to
> discuss this with you offline when time permits.
>
>
> >
> >Disclaimer : Those comments are engaging only their author, and
> must not be
> >considered as "official" feedback neither from the Topic Maps standard
> >working group (namely ISO/IEC JTC1/SC34-WG3), nor from the
> OASIS Published
> >Subjects TC that I happen to chair. Interoperability with OWL
> has not been
> >put on the agenda of those groups so far. That is something I personally
> >deplore, and that seems due to many reasons, among which: lack of task
> >force, "not developed here" syndrom, and last but least lack of formal
> >foundation for Topic Maps, making the whole TM community uneasy
> about the
> >issue.
> >
> >Before going to the specific point of Published Subjects, I want to say
> >that I have been working for some time now, on an OWL
> expression for Topic
> >Maps, trying to consider them as some specific kind of ontology
> - which I
> >think it should be, no more, no less. Although TM gurus have
> always claimed
> >them to be ontology-neutral, this is IMO wrong, the only way to be
> >ontology-neutral being to keep silent. And Topic Maps folks are
> known to be
> >very talkative :)
> >Difficulties that I meet to achieve that task seem to come, not from the
> >lack of expressive power of OWL, but from the lack of consensus for what
> >are the foundations of Topic Maps, default a consensus on their formal
> >model. "What is a topic map?" is still an open issue it seems. A good
> >reference for the state of reflection in TM community vs RDF
> and OWL is the
> >paper from Lars Marius Garshol "Living with Topic Maps and RDF" that he
> >will present this week at XML Europe:
> >http://www.ontopia.net/topicmaps/materials/tmrdf.html.
> >
> >Concerning Published Subjects, I will show below that OWL
> documents could
> >easily meet the Requirements and Recommendations for Published Subjects
> >expressed in Deliverable 1 of OASIS PubSubj TC [1], about to be
> adopted as
> >a TC specification (hopefully) in London next Friday:
> >http://www.ontopia.net/tmp/pubsubj-gentle-intro.htm.
> >
> >- Requirement 1:
> >"A Published Subject Identifier must be a URI."
> >
> >Sor far, so good. Any URI identifying an OWL class, property or
> individual
> >can be used as a Subject Identifier.
> >
> >- Requirement 2:
> >"A Published Subject Identifier must resolve to an human-interpretable
> >Published Subject Indicator."
> >
> >Are OWL ontologies human-interpretable? Depending on humans, of
> course. But
> >providing sensible use of labels and comments, an OWL element
> can be a very
> >accurate Subject Indicator for the class, property, or individual it
> >represents.
> >
> >- Requirement 3:
> >"A Published Subject Indicator must explicitly state the unique
> URI that is
> >to be used as its Published Subject Identifier."
> >
> >This is more tricky. Take for example
> >http://www.mondeca.com/owl/univ1_0.xml#Employee
> >Extracted from an attempt of re-writing a DAML university
> ontology in OWL)
> >
> ><owl:Class rdf:ID="Employee">
> >   <owl:sameAs
> >rdf:resource="http://www.mondeca.com/owl/general1_0.xml#Employee" />
> ></owl:Class>
> >
> >Here both http://www.mondeca.com/owl/univ1_0.xml#Employee and
> >http://www.mondeca.com/owl/general1_0.xml#Employee could be
> valid subject
> >identifiers. So, to be conformant to Requirement 3, either a
> general rule
> >should be set, or a specific explicit property should be set like
> >psi:identifier, in the following way.
> >
> ><owl:Class rdf:ID="Employee">
> >     <owl:sameAs
> >rdf:resource="http://www.mondeca.com/owl/general1_0.xml#Employee" />
> >     <psi:identifier
> >rdf:resource="http://www.mondeca.com/owl/univ1_0.xml#Employee" />
> ></owl:Class>
> >
> >This is to be discussed and settled, but the expressive power
> is here. Note
> >that the "sameAs" declaration leads to the important notion of
> equivalent
> >identifiers. A topic map application should be able to make
> sense of it by
> >aggregating on a single topic node its various subject identifiers in
> >various ontologies.
> >
> >- Recommendation 1:
> >"A Published Subject Indicator should provide human-readable
> metadata about
> >itself."
> >
> >This can be achieved by using specific DatatypeProperties, either at the
> >element level or at the ontology level, like the dc elements that can be
> >found in the above quoted ontology. Note that the TC has not decided yet
> >what kind of metadata are relevant, but there again the
> expressive power of
> >OWL can support a large variety of those.
> >
> >- Recommendation 2:
> >"A Published Subject Indicator may provide machine-processable metadata
> >about itself."
> >
> >No comment here. Metadata expressed in OWL are obviously
> >machine-processable.
> >
> >- Recommendation 3:
> >"Metadata defined in Recommendations 1 and 2 should be
> consistent, but need
> >not necessarily be equivalent."
> >
> >I figure human-readable metadata here being only a transcription of OWL
> >information in a more human-readable format than rdf.
> >
> >- Recommendation 4:
> >"A Published Subject Indicator should indicate that it is intended to be
> >used as a PSI."
> >
> >This can be specified in the ontology header.
> >
> >- Recommendation 5:
> >A Published Subject Indicator should identify its publisher.
> >
> >There again this information can be included in the ontology header.
> >
> >In conclusion, I consider OWL as a very convenient format for
> expression of
> >Published Subjects. Moreover, providing the few points quoted below are
> >cleraly settled, it could be possible to have a recommendation for
> >"PSI-in-OWL", approved both by OASIS PubSubj TC as conformant to its
> >Requirements and Recommendations, and by OWL-WG as a recommended
> >application of OWL.
> >
> >Again, I insist this is only so far a personal roadmap, I will put it on
> >the OASIS PubSubj TC agenda and see what happens there, and it's up to
> >OWL-WG to see if it also fits iis agenda.
> >
> >Thanks for your attention
> >
> >Bernard
> >
> >Bernard Vatant
> >Senior Consultant
> >Knowledge Engineering
> >Mondeca - www.mondeca.com
> >bernard.vatant@mondeca.com
> >
> >[1] Complete archives of PubSubj TC work are temporarily at
> >http://www.mondeca.com/pubsubj/
> >The official OASIS TC site is under reconstruction, due to CMS
> migration,
> >at:
> >http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=tm-pubsubj
>
> --
> 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	  *** 240-277-3388 (Cell)
> http://www.cs.umd.edu/users/hendler      *** NOTE CHANGED CELL NUMBER ***
>