Abstract
This thesis deals with the design of an annotation validation and enrichment service for an industrial knowledge management tool based on the Topic Maps language (TM). As such a service needs reasoning capabilities on knowledge, one part of the work was to provide formal semantics to the TM language. This has been done by a mapping between TM language and conceptual graph logical formalism (which - as TM - is close to graph theoretic structures). The designed solution has been used in two end-user applications : one for media monitoring and the other for touristic promotional needs. In a schematic way, annotations are automatically extracted from documents (with regard to the cultural field : news/economy/politics/tourism/etc) and merged with the knowledge base. In a second time, they are sent to an enrichment and validation service which completes the annotation and verify its consistence ; and finally send back to the KB the enrichment and validation results.