Metric Indexing for the Vector Model in Text Retrieval

Abstract. In the area of Text Retrieval, processing a query in the vector model has been verified to be qualitatively more effective than searching in the boolean model. However, in case of the classic vector model the current methods of processing many-term queries are inefficient, in case of LSI model there does not exist an efficient method for processing even the few-term queries. In this paper we propose a method of vector query processing based on metric indexing, which is efficient especially for the LSI model. In addition, we propose a concept of approximate semi-metric search, which can further improve the efficiency of retrieval process. Results of experiments made on moderate text collection are included.