Natural sentence retrieval device, natural language search method, natural language search program storage medium and natural language search program

摘要

PROBLEM TO BE SOLVED: To increase possibility that a document including an answer to a question sentence is included in a retrieval result regardless of the number of keywords extracted from the question sentence by a natural language.;SOLUTION: The keyword is extracted from the question sentence by the inputted natural language (3), an importance level of the keyword is calculated (4), upper n words are designated as essential conditions (AND conditions) for keyword retrieval, the other keywords are included in preferential conditions (OR conditions) (5), a document retrieval device 7 is made to perform the keyword retrieval, and a result thereof is displayed (9). Thereby, even when a user inputs a long question sentence, the document including the important keyword and a large number of other keywords is retrieved and is ranked, so that the possibility that the document including the answer to the question sentence is included in the retrieval result can be increased.;COPYRIGHT: (C)2005,JPO&NCIPI