Querying Heterogeneous and Distributed Learning Object Repositories via Ontology-Based Mediation

We propose an ontology-based mediation approach which enables an e-learning system to query several heterogeneous LO (learning object) repositories. After analysing and representing the knowledge representation and the metadata structure of a repository it is easy to use the repository as a service by specifying a wrapper which calls the retrieval facilities of the new repository. This technique was successfully implemented and tested for the e-learning environment ActiveMath and four repositories