- From: Guus Schreiber <schreiber@swi.psy.uva.nl>
- Date: Wed, 26 Jun 2002 15:10:23 +0200
- To: www-rdf-interest@w3.org
- CC: Stefan Decker <stefan@db.stanford.edu>
Exploiting corpora such as WordNet and the Art and Architecture Thesaurus is (at least from our perspective) essential for making the vision of a semantic web come true. In practice however, using an RDF representation of WordNet poses a number of problems. We are currently looking at the (unofficial) RDF-WordNet developed by Sergey Melnik and Stefan Decker [1]. They provide an RDF Schema with class definitions for "LexicalConcept" (i.e. a synset) and its subclasses (noun, verb, ...). as well as property definitions for "wordForm" (synset -> term), "glossaryEntry" (synset -> description) and "hyponymOf (synset -> synset). The WordNet corpus itself is represented as RDF files with instances of these schema definitions. One disadvantage of this representation is that the WordNet hierarchy is now "hidden" in the hyponymOf triples. One could therefore argue that this representation is wrong. However, if the semantic web really becomes a reality, different representation choices will be a fact of life. So, we looked at a neat way of defining our interpretation of "WordNet as a class hierarchy" as an add-on RDF Schema. It turned out that with two definitions we could solve this problem: 1. wn:LexicalConcept rdfs:subClassOf rdfs:Class 2. wn:hyponymOf rdfs:subPropertyOf rdfs:subClassOf In addition, we included: 3. wn:wordForm rdfs:subPropertyOf rdfs:label 4. wn:glossaryEntry rdfs:subPropertyOf rdfs:comment which also seems to make sense. See [2] for the RDF Schema file. Although it first seemed like a hack, on second thought this might actually be a decent way to do this kind of ontology/representation mapping. Note that this approach makes heavy use of RDF's metamodelling facilities. Comments/suggestions are very welcome, Guus Schreiber P.S. This work is done in the context of research on semantic image annotation and search [3]. Up till now, we are using our own RDF-WordNet conversion. However, for realistic applications we believe we should use as much as possible publicly available web resources (and solve the resulting representation mapping problems). [1] http://www.semanticweb.org/library#wordnet [2] http://www.swi.psy.uva.nl/usr/Schreiber/schema/wnclass.rdfs [3] http://www.swi.psy.uva.nl/usr/Schreiber/papers/Schreiber01a.pdf -- A. Th. Schreiber, SWI, University of Amsterdam, Roetersstraat 15 NL-1018 WB Amsterdam, The Netherlands, Tel: +31 20 525 6793 Fax: +31 20 525 6896; E-mail: schreiber@swi.psy.uva.nl WWW: http://www.swi.psy.uva.nl/usr/Schreiber/home.html
Received on Wednesday, 26 June 2002 09:27:29 UTC