- From: Johannes Busse <busse@ontoprise.de>
- Date: Wed, 25 Mar 2009 09:11:43 +0100
- To: SKOS <public-esw-thes@w3.org>
- CC: Bernard Vatant <bernard.vatant@mondeca.com>
Dear SKOS editors, (my personal view:) I'm working at a little company, which provides a nice and fast ontology language (called F-logic, which is sort of a enhanced datalog). We also have an own OWL reasoner implementation (which does OWL DL A-Box inferencing pretty fast). And of course we have an ontolog engineering environment (called OntoStudio) which allows for an (as far this is possible) integrated view on F-logic and OWL. The industrial customers of our semantic technologies want to be sure that we provide inferencing which is sound and complete. They explicitely require that we do not apply "semantic heuristics" which are not well defined. This means that from a contractual point of view we are not allowed to prune a 3rd party OWL full ontology into an OWL DL (or OWL2 EL, OWL2 R etc) ontology. After long discussions we have decided *not* to support even *loading* OWL full ontologies into our systems. Why? While we of course often can *guess* which parts of an OWL full ontology are there mainly in order to communicate the understanding of an ontology (as opposed to do inferencing with it) we do not *know* that for sure. I.e. we cannot prove that a specific semantic model for our customer is at least correct when there was an OWL full ontology in the chain. As a result we cannot use the skos2008 version as it is. As long as there is only an OWL full version of SKOS this standard remains academic. We simply stick to skos2004 until things get better. I understand that things will become much better when OWL2 is finished. (But please give us some time and resources to implement OWL2 then; it's pretty complex). For the time being I'd like to ask whether it is possible for you to provide a "semantic skeleton" of skos2008, which has to be sound and complete, but neverttheless equivalent to your intended semantics of skos 2008. This is something which has to be done by the authors themself, because we are speaking here of standards and intentions. This also would help to communicate the very core of the skos idea in a simple way. yours Johannes PS: Using skos 2008 (i.e. integrating it with other ontolgies) additionally would be even more interesting if the semantic skeleton of skos2008 would prove to be OWL1 ultralite, OWL2 EL, OWL2 RL or any other *fast and simple* OWL2 profile. (Even OWL DL ist to complex to allow for large scale inferencing.) Then skos would in faxt remain a simple KOS, which could in fact act as a very nice, lightweight and powerful (1) stand alone starting point and (2) extension to many other ontology projects. Bernard Vatant wrote: > Hello > > I'm not sure SKOS editors were aware of the behavior of various OWL > ontology editors regarding the handling of the annotation properties > (labels and documentation) in the current SKOS model. > To declare rdfs:subPropertyOf relationships between annotation > properties is definitely a OWL-Full feature at least in OWL 1.0. I can > read in the reference document that this feature "makes SKOS more usable > with the OWL 2 specification currently in development". Not sure about > what will come out of OWL 2.0, but when using OWL 1.0 ontology editors, > this situation leads to various inconsistent behaviours. Basically they > do not support this kind of construction, and they get rid of it in > different ways. > > Examples: > > SWOOP 2.3 latest (and last) release - I know this one is a bit old and > no more under development, but I keep using it default of better free > lightweight tool. > The rdfs:subProperty relationships between annotation properties are > simply ignored, and if you save the model, they are definitely off. > > Protégé 4.0 decides that "pure" annotation properties can't be the > subject of assertions, so it considers all the annotation properties > participating in the subproperty statements are object properties (but > still annotation properties), which seems weird to me. There again, if > the model is saved, properties are saved this way. > > Remarkably enough, none of those tools signal any error or trigger any > warning when loading the file. Which is unfortunate indeed. > It's been a daily routine in Mondeca to merge the SKOS model into wider > customer ontologies we manage with the above editors. > And I guess we are not alone in this case. > > I have no solid proposal to deal with that issue, but just wondering if > others have stumbled on it. > > Cheers > > Bernard > -- Dr. Johannes Busse, Senior Researcher An der RaumFabrik 29, D-76227 Karlsruhe Reg. Office: Karlsruhe, Amtsger. Mannheim, HRB 109540 Managing Directors: Prof.Dr.J.Angele, H.P.Schnurr http://www.ontoprise.de | phone x49(721) 509 809-62 mailto:busse@ontoprise.de | mobile x49(163) 509 80-62
Received on Wednesday, 25 March 2009 08:06:36 UTC