Les treillis de Galois Alpha

Our basic representation of the data is a Galois lattice, i.e. a lattice in which the terms of a representation language are partitioned into equivalence classes w.r.t. their extent (the extent of a term is the part of the instance set that satisfies the term). We propose here to simplify our view of the data, still conserving the Galois lattice formal structure. For that purpose we use a preliminary partition of the instance set, representing the association of a type to each instance. By redefining the notion of extent of a term in order to cope, to a certain degree (denoted as α), with this partition, we define a particular family of Galois lattices denoted as Alpha Galois lattices. MOTS-CLÉS : classification non-supervisée, treillis de Galois, règles d’association.