Ontology mapping involves the task of finding similarities among overlapping sources by using ontologies. In a Federated System in which distributed, autonomous and heterogeneous information sources must be integrated, ontologies have emerged as tools to solve semantic heterogeneity problems. In this paper we propose a three-level approach that provides a semi-automatic method to ontology mapping.
It performs some tasks automatically and guides the user in performing other tasks for which his/her intervention is required. Finally, a plug-in of the ontology editor, Protégé, is presented showing how the method is implemented through a case study.