For classifying wine amphoras used at the end of the Roman Republic and the beginning of the Empire (the so-called Dressel 2–4), we present a typological approach which combines a classification algorithm with the archeological reasoning. At the first step, clusters contain only nuclei based on the different production areas. To assign a corpus of artifacts to them, it is divided for each cluster into a context (artifacts which certainly do not belong to the cluster) and a residue. For each cluster, we built characteristic definitions with logical discriminant function of morphological attributes. Each definition cuts the residue in two classes: one containing the artifacts assigned to the cluster by the definition and the complementary one in the residue. Assignment and choices of cluster definitions and context remain with the archeological expert, who submits those typological constructions to a validation process founded on archeological knowledge. Such an approach focuses on a very common situation in human sciences: the construction of a cognitive typology beginning with a partially clustered set. Clustering must be done with descriptive attributes, without knowing if they can be connected with the wanted cluster.