Document retrieval system

Claim 1

A document retrieval system comprising: keyword connection table making means for making a keyword connection table which describes a weight of each keyword connection among a first set of keywords from each of documents registered in a database file, and, upon request, the keyword connection table making means acting to update a weight of a keyword connection pre-recorded on a keyword connection table file to make a new keyword connection table containing a modified weight of the keyword connection; document selection means including means for selecting output documents from the database file by reference to the keyword connection table file, the output documents being in conformity with a query containing a second set of keywords initially given by a user; document accuracy calculating means for calculating a document accuracy which is obtained with a weight of each keyword connection between a third set of keywords from a document out of the output documents and the second set of keywords from the query when the user modifies a document accuracy of the document, the document accuracy calculating means computing a document accuracy for each of the output documents in a prescribed manner by reference to the keyword connection table; document sorting means for sorting the output documents in downward sequential order of the document accuracy computed by the document accuracy calculating means; learning control means for modifying a weight of each keyword connection previously assigned between the third set of keywords from the document and the second set of keywords from the query in a prescribed manner when the user makes an evaluation on whether the document accuracy of the document previously computed by the document accuracy calculating means is in conformity with the query after the output documents are aligned by the document sorting means in downward sequential order of the document accuracy previously computed by the document accuracy calculating means; and means for providing the user with multiple choices of a numerical value between 0 and 1 for each document accuracy of the output documents when the suer inputs an evaluation value to the document retrieval system after making the evaluation on whether the document accuracy of each of the output documents is in conformity with the query, the multiple choices each including binary 0 and 1 representing two distinctly opposed evaluations made by the user with respect to the query, or 0 being not in conformity with the query and 1 being in conformity with the query, the multiple choices each further including any intermediate numerical value between 0 and 1 representing an ambiguous evaluation, made by the user, that cannot be represented by the two distinctly opposed evaluation only.