A current application of automatic text summarization is to provide an overview of relevant documents coming from an information retrieval (IR) system. This paper examines how Centrifuser, one such summarization system, was designed with respect to methods used in the library community. We have reviewed these librarian expert techniques to assist information seekers and codified them into eight distinct strategies. We detail how we have operationalized six of these strategies in Centrifuser by computing an informative extract, indicative differences between documents, as well as navigational links to narrow or broaden a user’s query. We conclude the paper with results from a preliminary evaluation.