The information retrieval device and machine reading possible record media null which records the program

摘要

PROBLEM TO BE SOLVED: To efficiently conclude retrieval result data in an information retrieval device. SOLUTION: A retrieval execution part 203 retrieves a retrieval object data base 204 based on a retrieval condition which a user inputs. A concluding execution part 209 obtains the common node of respective leafs pointing retrieval result data retrieved in the retrieval execution part 203 among the nodes in a hierarchy structure index 208 as a question node and obtains the nodes existing in a hierarchy just below respective question nodes as answer nodes. The respective question nodes are indicated to the user in a system where the priority of narrowing efficiency at the time of selecting the respective question nodes can be recognized. Then, retrieval result data retrieved in a retrieval execution part 203 is narrowed based on the answer node which the user selects among the answer nodes to the question node which the user selects.