TEXT RETRIEVAL DEVICE, TEXT RETRIEVAL METHOD, TEXT RETRIEVAL PROGRAM AND RECORDING MEDIUM RECORDING THE PROGRAM

摘要

PPROBLEM TO BE SOLVED: To provide text retrieval technology for improving processing performance of retrieval processing when using inverted files in impact value order. PSOLUTION: This text retrieval device 1 has a retrieval processor 20. The retrieval processor 20 has: a retrieval condition input means inputting a retrieval condition 101 designated by a plurality of words or the like; a word extraction means extracting an inputted word group 102 based on a word dictionary; a word group classification means classifying the respective extracted words into a word group having low df values and a word group having high df values based on the previously calculated df values; a candidate document search means using the inverted files 71, 74 in the impact value order constructed in each word about the word group having the low df values, and searching for a candidate document that is an output candidate by use of an inverted file 73 in document ID order constructed in each word about the word group having the high df values; and a candidate document output means deciding and outputting the candidate documents d16, etc. at the time of satisfying the retrieval condition. PCOPYRIGHT: (C)2009,JPO&INPIT