Patent ID: 7467132
Filing Date: 2008-12-16
Classification: G06F,Y10S

Abstract:
1. A searching apparatus comprising: processor means; storage means for storing search object data; means for selecting a population from the stored object data; means for providing information for determining an exclusion keyword to be specified for an efficient exclusion to exclude a piece of data associated with a specified exclusion keyword from pieces of searching object data stored in said storage means, wherein an exclusion efficiency indicates a level of exclusion efficiency of data for an individual keyword associated with said searching object data when said keyword is specified as said exclusion keyword; said means for providing information for determining an exclusion keyword comprises means for determining an exclusion efficiency of excluding a piece of data associated with a specified keyword comprising means for calculating exclusion efficiency for an individual keyword associated with said searching object data, based on a first parameter indicating a level of exclusion efficiency of data in a set of part of said searching object data when said keyword is specified as said exclusion keyword and a second parameter indicating a level of exclusion efficiency of data in a set of all of said searching object data when said keyword is specified as said exclusion keyword; wherein said exclusion efficiency increases as the value of said first parameter is smaller, and increases as the value of said second parameter is greater; said first parameter indicating the intensity of correlation between a selection keyword and an exclusion keyword wherein the value of the first parameter is greater with stronger correlation between the selection keyword and the exclusion keyword, said first parameter being calculated using the following formula: where X is a searching object population set, T(X, word0) is a set of document data in which keyword0 appears in the set X, and #(X) denotes the number of elements in the set X, and the second parameter is a value indicating the number of documents excluded by specifying the exclusion keyword, wherein the calculation expression for the second parameter is set up so that the value of the second parameter is greater when more documents are excluded, the selection keyword is “word0” and the exclusion keyword is “word1”, wherein the second parameter is calculated employing the following formula: where T(X, word1) is a set of document data in which keyword1 appears in the set X, wherein the exclusion efficiency calculator calculates exclusion efficiency from the first and second parameters in accordance with the following formula, which satisfies the conditions where the exclusion efficiency increases as the first parameter is smaller, and increases as the second parameter is greater: where 0<a<1, the first and second parameters taking a value from 0 to 1, whereby the exclusion efficiency has a value from 0 to 1; wherein said providing means provides said information in a format of making a difference between the contribution levels of said first parameter and said second parameter to said exclusion efficiency clear; and means for providing said exclusion efficiency to a user.