Formalizing for querying learning objects using OWL

The World Wide Web offers an increasing amount of complex and rich educational Web resources that are available for free in various domains. Unfortunately, it is difficult today to have a Web agent that answers precisely a simple query. Semantic Web aims to make Web resources meaningful to automated agents. Ontologies are proposed to provide a formal representation of a shared and common conceptualization of a specific domain. For the description of educational resources several communities are working on the definition of metadata elements. The Learning Technology Standards Committee (LTSC) specifies the Learning Object Metadata (LOM), a set of elements describing the relevant characteristics for learning resources. The goal of this paper is to give a formal and more comprehensive content description of learning resources in order to allow better reusability and retrievals. This description is particularly focused on the semantic relationships between learning resources which constitute an important aspect to access information. It uses OWL, an ontology language for the semantic Web, recently developed by the W3C. OWL provides powerful expressiveness combined with desirable computational properties for reasoning systems due to its correspondence with description logics. The query of the corresponding knowledge base is illustrated using OWL Query Language OWL-QL.