The lack of accuracy of an information retrieval system (IRS) may be due to an inadequate formulation of user's queries. Reformulation or query expansion is a possible solution to this problem. In this paper, we introduce a reformulation method based upon a domain ontology. This conceptual relevance feedback method uses a set of documents a user has deemed relevant to search a set of concepts that maximizes IRS performances. Those performances are assessed in an original way, using indicators that are formalized. This method has been evaluated using our environment OBIRS (Ontology Based Information Retrieval System) as base system, MeSH as domain ontology and MuCHMORE as a test collection. MOTS-CLES: Reformulation de requete, ontologie, Systemes de Recherche d'Information, requetes conceptuelles, expansion de requetes.
['Mohameth François Sy', 'Sylvie Ranwez', 'Jacky Montmain', 'Vincent Ranwez']
OBIRS-feedback, une méthode de reformulation utilisant une ontologie de domaine