Clustering of Symbolic Objects Described by Multi-Valued and Modal Variables

In this paper we investigate the problem of the determination of the number of clusters for symbolic objects described by multi-valued and modal variables. Three dissimilarity measures are selected in order to define distances on the set of symbolic objects. Methods for the determination of the number of clusters are applied to hierarchies of partitions produced by four hierarchical clustering methods, and to sets of partitions given by the symbolic clustering procedure SCLUST. Two real data sets are analysed.