Patent ID: 6208987
Filing Date: 2001-03-27
Classification: G06F,Y10S

Abstract:
An information retrieval system comprising:a retrieval object database for storing a plurality of retrieval object data;means for providing hierarchically-structured indexes constructed by a plurality of nodes and a plurality of leaves, wherein each of the plurality of nodes is connected with at least one node and/or at least one leaf which are located one level of hierarchy below therefrom, andwherein each of the plurality of leaves has an index of each of the plurality of retrieval object data;retrieval execution means for retrieving through the retrieval object database based on a retrieval condition input by a user so as to obtain retrieval result data; andnarrowing-down execution means for obtaining question nodes corresponding to common nodes commonly connected with leaves pointing to the retrieval result data retrieved by the retrieval execution means within the hierarchically-structured indexes and for obtaining answer nodes that are located at a level of hierarchy just below a level of hierarchy to which each of the question nodes belongs, wherein narrowing-down factors are calculated with respect to the question nodes respectively so that the question nodes are presented for the user in a form that the user is capable of recognizing merits of the narrowing-down factors, whereby the narrowing-down execution means narrows down the retrieval result data on the basis of the answer node that is selected by the user within the answer nodes to the question nodes selected by the user;an information retrieval system wherein each of the plurality of nodes is set to have content of classification, which is hierarchically performed in a prescribed aspect on the retrieval object data stored in the retrieval object database;wherein the narrowing-down execution means further comprisesfirst means, activated when leaves pointing to same retrieval result data exist in a level of hierarchy below a level of hierarchy to which the answer nodes belong, for newly obtaining nodes belonging to the same level of hierarchy of the answer nodes as new question nodes and for newly obtaining nodes located at a level of hierarchy just below the level of hierarchy of the new question nodes as new answer nodes, andsecond means, activated when leaves pointing to retrieval result data related to the new question nodes belong to a same level of hierarchy and when a level of hierarchy of the new question nodes is one level of hierarchy above the level of hierarchy of the leaves or is identical the level of hierarchy of the leaves, for disallowing utilization of the new question nodes.