Abstract: A method is disclosed for evaluating an information retrieval system. A performance metric is associated with a message received at the information retrieval system. A geometric point is determined that corresponds to the message based on one or more clustering techniques. The message is assigned to a cluster based on a judgment of a distance between the geometric point and an additional geometric point, the additional geometric point corresponding to an additional message, the additional message being assigned to the cluster. The performance metric is aggregated with an additional performance metric, the additional performance metric corresponding to the additional message. A value is assigned to the cluster, the value representing a ranking of the cluster in comparison to an additional cluster with respect to the performance metric and the additional performance metric.