- From: Morten Christensen <mortench2003@yahoo.dk>
- Date: Thu, 11 Sep 2003 11:53:57 +0200 (CEST)
- To: www-rdf-interest@w3.org
- Cc: office@e-senses.de
- Message-ID: <20030911095357.89627.qmail@web12901.mail.yahoo.com>
Benjamin Nowack <office@e-senses.de> wrote: >hmm. wouldn't the only question you can ask a reasoner be: >"which articles exist that ARE_A WineGrape?"? No, since this is really an taxonomy this example (as you would say: ) "misuse" IS_A as a NARROWER/BROADER relation and INSTANCE_OF as an ABOUT relation. >In order to be able to ask "is_about" you would need an >ObjectProperty beforehand to relate two things plus a class >definition for "Article"... >...To be honest, this is such an obvious misuse of not only >subClassOf but of the whole OWL language that I don't think >that modelers will really go that way. As you say one can express the required relations in the standard OWL way using proper ontogical constructs based on descriptive logic. I think we all agree that one should do that if the intend is to produce ontologies that allow software to interoperate (for the semantic web). However for the taxonomist, I think that what you suggest would be more complex and more expensive (*).... In particular, my key problem with your ontological approach is that it appears not to provide out-of-the-box reasoner support for my classification question: "which (articles) exist that are about WineGrape?" (If I am wrong about the reasoner support for your apprach, please let me know - I would be very interested!!) Note that with the taxonomy approach out-of-the-box reasoner support does exist, since the reasoner will propagate instances (informantion object) UP(!!) the class (topic/subject) inheritance chain. This makes is possible to give correct answers to all needed taxonomy and classification questions. (*) This is important as many taxonomists do not have a background in mathematics or computer science AND very few companies with just the need for a taxonomy for their information will be willing to spend more than necessary in order to satisfy academic concerns. >And it will be hard >to use a "commonly available" OWL editor as well: imagine >you want to add separate class for books and websites (e.g. >in order to automatically generate a link to amazon or a >link to the website, depending on the type of the information >object). Where do you add these classes in your taxonomy?: One way would be to use facet classification, so we still have: - Grape - WineGrape - CabernetSauvignonGrape (3 instances below) + RestaurantThatServesCabernetSauvignon + BookAboutCabernetSauvignonGrape + WebSiteAboutCabernetSauvignonGrape AND - Object - Book (1 instance below) + BookAboutCabernetSauvignonGrape AND - Object - Website (1 instance below) + WebSiteAboutCabernetSauvignonGrape That is the traditional way to do it. It should cause no problems for any OWL tools including reasoners (as long as it restricts itself to taxonomies only). >You might say: "Bad example. Yes :-) >I think we won't get a problem either because if you only >have one type of instance, then your taxonomy is valid. >You just labeled your classes in a way that leads to >confusion. Rewritten taxonomy: > >- InfoObject >InfoObjectAboutGrape >InfoObjectAboutWineGrape >InfoObjectAboutCabernetSauvignonGrape >... > >All the way nice "isSublassOf" relations... The labels are written as they typical would be in a taxonomy. Your point about renaming is interesting, but consider what will happen when a reasoner runs on a mix of my OWL taxonomy and a OWL wine ontology. Greetings, M. Christensen ------------ Yahoo! Mail - Gratis: 6 MB lagerplads, spamfilter og virusscan
Received on Thursday, 11 September 2003 05:53:58 UTC