DOCUMENT RETRIEVAL DEVICE, DOCUMENT RETRIEVAL METHOD, DOCUMENT RETRIEVAL PROGRAM AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To output an appropriate retrieval result to a retrieval request. SOLUTION: The document retrieval device for executing retrieval to a predetermined group of document information based on a retrieval word and a relevant word comprises an input means for inputting the retrieval word; a relevant document retrieval means for acquiring a group of document information retrieved based on the retrieval word from a second group of document information different from the predetermined group of document information as relevant document information; and a relevant word extraction means extracting the relevant word from the relevant document information. COPYRIGHT: (C)2007,JPO&INPIT