MELISA. An ontology-based agent for information retrieval in medicine

This paper describes MELISA MEdical Literature Search Agent – a prototype of an ontology-based information retrieval agent. We have designed a modular system that can be easily adapted to another medical lit erature sources or other professional domains. The major issues are the design of an architecture with three levels of abstraction, the use of separated ontologies and query models, and the definition of some aggregation operators to combine results from different queries.