Nonparametric Bayesian Co-clustering Ensembles

A nonparametric Bayesian approach to co-clustering ensembles is presented. Similar to clustering ensembles, coclustering ensembles combine various base co-clustering results to obtain a more robust consensus co-clustering. To avoid pre-specifying the number of co-clusters, we specify independent Dirichlet process priors for the row and column clusters. Thus, the numbers of rowand column-clusters are unbounded a priori; the actual numbers of clusters can be learned a posteriori from observations. Next, to model non-independence of rowand column-clusters, we employ a Mondrian Process as a prior distribution over partitions of the data matrix. As a result, the co-clusters are not restricted to a regular grid partition, but form nested partitions with varying resolutions. The empirical evaluation demonstrates the effectiveness of nonparametric Bayesian co-clustering ensembles and their advantages over traditional co-clustering methods.