- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Fri, 20 Jun 2003 09:34:15 +0200
- To: "Public-Webont-Comments@W3. Org" <public-webont-comments@w3.org>
- Cc: "tm-pubsubj" <tm-pubsubj@lists.oasis-open.org>
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 *** >
Received on Friday, 20 June 2003 03:34:23 UTC