%0 Report %9 Technical Report %A Klein, Dan %A Kamvar, Sepandar D. %A Manning, Christopher D. %D 2002 %F ilprints:528 %I Stanford InfoLab %K clustering, constrained clustering, prior knowledge %T From Instance-level Constraints to Space-Level Constraints: Making the Most of Prior Knowledge in Data Clustering %U http://ilpubs.stanford.edu:8090/528/ %X We present an improved method for clustering in the presence of very limited supervisory information, given as pairwise instance constraints. By allowing instance-level constraints to have space-level inductive implications, we are able to successfully incorporate constraints for a wide range of data set types. Our method greatly improves on the previously studied constrained k-means algorithm, generally requiring less than half as many constraints to achieve a given accuracy on a range of real-world data, while also being more robust when over-constrained. We additionally discuss an active learning algorithm which increases the value of constraints even further.