In order to measure the similarity between two partitions coming from the same data set, we study extensions of the RV-coefficient, the kappa coefficient proposed by Cohen (in case of partitions with same number of classes), and the D2 coefficient proposed by Popping. We find that the RV coefficient is identical to the Janson and Vegelius index. We compare the result coming from kappa’s coefficient to the ordination given by correspondence analysis. We study the empirical distribution of these indices under the hypotheses of a common partition. For this purpose, we use data coming from a latent profile model to formulate the null hypothesis.