INFORMATION RETRIEVAL METHOD, DEVICE, PROGRAM, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To perform ranking retrieval targeting a large-scale document set at high speed and low costs. SOLUTION: A retrieval processing part 7 inputs an appearance location list of an index word from a high-frequency word transposition index 4 in which a list of index words and appearance locations of documents of which the frequencies of the index word are equal to or more than a threshold F is stored when a search word is constituted of only one index word, inputs the appearance location list of the respective index words from the high-frequency word transposition index 4 when the retrieval word is a line of a plurality of index words, calculates a list of locations where all the index words adjacently appear, transfers the list to an adaptation calculation part 6 and receives an adaptation document list. When the obtained adaptation document list refers to T or more documents required for display of retrieval results and when documents with top T-th adaptation have adaptation larger than the maximum adaptation which can be taken by low-frequency documents not to be stored in the high-frequency word transposition index 4, they are outputted. COPYRIGHT: (C)2004,JPO&NCIPI