DOCUMENT RETRIEVAL METHOD, EXECUTING DEVICE THEREOF, AND STORAGE MEDIUM WITH ITS PROCESSING PROGRAM STORED THEREIN

摘要

PROBLEM TO BE SOLVED: To provide a technique capable of retrieving a proper related word according to a user's intension and improving the efficiency of a document retrieval work. SOLUTION: This document retrieval method for retrieving a desired document from a document database by use of a keyword comprises the step of extracting a related word related to the inputted keyword and the effective period of the related word; the step of performing the retrieval of document by use of the extracted related word as a retrieval word, and the step of selecting a document within the extracted effective period from the retrieved documents.