In this paper we describe a mechanism to improve Information Retrieval (IR)
on the web. The method is based on Formal Concepts Analysis (FCA) that it is
makes semantical relations during the queries, and allows a reorganizing, in
the shape of a lattice of concepts, the answers provided by a search engine. We
proposed for the IR an incremental algorithm based on Galois lattice. This
algorithm allows a formal clustering of the data sources, and the results which
it turns over are classified by order of relevance.