Abstract: The characteristics of the entire gene group including a plurality of genes can be readily grasped. A plurality of search keys are accepted from a client, and a set of document groups each corresponding to the plurality of the accepted search keys is obtained, referring to a table where correspondence relationships between the search keys and the document groups are recorded. Then, a characteristic word list having the levels of relative importance is prepared in each of the search keys, and a characteristic table is prepared on the basis of the characteristic word lists. Finally, characteristic table is sorted, colored, and displayed.