| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an information retrieval technology for reducing a load to be imposed on user operation, and for supporting the user to easily acquire his or her desired document information. <P>SOLUTION: A unique expression extraction part 202 acquires a unique expression class to which a keyword extracted from a retrieval sentence belongs, and a retrieval sentence analyzing part 203 acquires the keyword and clue expressions from the retrieval sentence. A unique expression knowledge storage part 204 makes a unique expression class extension knowledge storage part 205 store the unique expression class and the clue expressions. A retrieval part 206 retrieves an internal document database 209 by using the unique expression class, the keyword and the clue expressions. When there is no corresponding program information, the retrieval part 206 retrieves an internal document database 209 by using the keyword and co-occurrence words retrieved by a co-occurrence word retrieval part 208. A unique expression class extension part 207 extends the unique expression class, and a co-occurrence word retrieval part 208 retrieves the keyword and the words co-occurring with the extended unique expression class in the internal document database 209. <P>COPYRIGHT: (C)2011,JPO&INPIT |
