Conroy, JohnO'Leary, Dianne P.A sentence extract summary of a document is a subset of the document's sentences that contains the main ideas in the document. We present two approaches to generating such summaries. The first uses a pivoted QR decomposition of the term-sentence matrix in order to identify sentences that have ideas that are distinct from those in other sentences. The second is based on a hidden Markov model that judges the likelihood that each sentence should be contained in the summary. We compare the results of these methods with summaries generated by humans, showing that we obtain higher agreement than do earlier methods. (Cross-referenced as UMIACS-TR-2001-11)en-USTechnical Report