Defining Several Ontologies to Enhance the Expressive Power of Queries

The use of ontologies is a key step forward for describing the semantics of information on the Web. It is becoming more and more important to make the information machinereadable, since the volume of data is continuously growing. In the educational area, metadata are considered to be helpful in such a process. We propose to enrich the description of educational resources by introducing several levels of description of concepts, and to make them machinereadable by using a formal language of ontology, OWL. Using both this ontology and the expressive power of an OWL query language to query pedagogical resources will improve the retrieval and interchange of educational resources.