Phase-Based Information Retrieval

ÐIn this article we describe a retrieval schema which goes beyond the classical information retrieval keyword hypothesis and takes into account also linguistic variation. Guided by the failures and successes of other state-of-the-art approaches, as well as our own experience with the IRENA system, our approach is based on phrases and incorporates linguistic resources and processors. In this respect, we introduce the phrase retrieval hypothesis to replace the keyword retrieval hypothesis. We suggest a representation of phrases suitable for indexing, and an architecture for such a retrieval system. Syntactical normalization is introduced to improve retrieval e€ectiveness. Morphological and lexico-semantical normalizations are adjusted to ®t in this model. # 1998 Elsevier Science Ltd. All rights reserved