Patent ID: 7412435

Claim:
An information retrieval apparatus that retrieves information from a plurality of data bases that accumulate different information, the information retrieval apparatus comprising: a data base identification unit that identifies one of the plurality of data bases according to a user's operation; a selection unit that preferentially selects, from a group of keywords indicating the user's preferences, one or more strongly preferred keywords based on a number associated with a use frequency of the data base identified by said data base identification unit; and a retrieval unit that retrieves information including the one or more keywords selected by said selection unit from the data base identified by said data base identification unit, wherein said selection unit includes: a keyword storage unit that stores, in advance, the group of keywords and a weight value indicating a degree of the user's preference for each of the keywords included in the group of keywords; a threshold storage unit that stores thresholds, in advance, each of the thresholds being associated with a use frequency for a corresponding one of the plurality of data bases; and a keyword selection unit that reads out the threshold associated with the data base identified by said data base identification unit, and that selects, from the group of keywords stored in said keyword storage unit, one or more keywords having a weight value which is (i) equal to or larger than the read-out threshold or (ii) equal to or smaller than the read-out threshold.