... for as-sessing therelative decrease in retrieval performancewhen indexing summaries instead of full documents.The idea behind it is similar to (Sparck-Jones andSakai, 2001). In that experiment, ... summarizers.1 IntroductionAutomatic document summarization is a field thathas seen increasing attention from the NLP commu-nity in recent years. In part, this is because sum-marization incorporates ... a corpus of doc- uments Di, a search engine ranks all documents in Diaccording to their relevance to the query Q. Ifinstead of the corpus Di, the respective summariesof all documents are...