A New Modification of the Rand Index for Comparing Partitions

The comparison of different partitions is an essential problem in evaluating numerical classifications. Measures of the similarity between partitions can be used not only to compare the results obtained from different cluster analyses, but also to compare the known structure of a data set with the result of a cluster analysis. A large number of such indices have been proposed. Reviews and comparisons are, for example, given in (1, 5, 7, 11, 12, 15). Especially (11) appears to reveal the fact that a modification of the Rand index (14) as described in (8) is particularly suitable for measuring the similarity between partitions.