Abstract
This chapter proposes an original approach for ontology management in the context of Web-based information systems. Our approach relies on the usage analysis of the chosen Web site, in complement of the existing approaches based on content analysis of Web pages. Our methodology is based on the knowledge discovery techniques mainly from HTTP Web logs and aims at confronting the discovered knowledge in terms of usage with the existing ontology in order to propose new relations between concepts. We illustrate our approach on a Web site provided by French local tourism authorities (related to Metz city) with the use of clustering and sequential patterns discovery methods. One major contribution of this chapter is thus the application of usage analysis to support ontology evolution and/or web site reorganization.