Filters and Answers: The University of Iowa TREC-9 Results

Our approach to filtering involves a two-level dynamic clustering technique. Each filtering topic is used to create a primary cluster that forms a general profile for the topic. Documents that are attracted into a primary cluster participate in a topic-specific second level clustering process yielding what we refer to as secondary clusters. These secondary clusters, depending upon their status, are responsible for declaring, i.e., retrieving, documents for the topic.