Abstract Clustering with constraints is a powerful method that allows users to specify background knowledge and the expected cluster properties. Significant work has explored the incorporation of instance-level constraints into non-hierarchical clustering but not into hierarchical clustering algorithms. In this paper we present a formal complexity analysis of the problem and show that constraints can be used to not only improve the quality of the resultant dendrogram but also the efficiency of the algorithms. This is particularly important since many agglomerative style algorithms have running times that are quadratic (or faster growing) functions of the number of instances to be clustered. We present several bounds on the improvement in the running times of algorithms obtainable using constraints.
A formal complexity analysis of constraints on transactions and clusters is performed in REF .
Using instance-level constraints in agglomerative hierarchical clustering: theoretical and empirical results
Data Mining and Knowledge Discovery
Data Mining and Knowledge Discovery
Computer Science