The present invention relates to data analysis for evaluating a plurality of pieces of object data; and the evaluation corresponds to the relation between each piece of object data and a specified case. An index that enables ranking of the plurality of pieces of object data is generated by the evaluation and the index changes based on an input entered by a user. A pattern is extracted that characterizes the reference data from the reference data according to the classification information assigned by the input. The index is determined by evaluating the relation between the object data and the specified case based on the extracted pattern and set to the object data. The plurality of pieces of object data are ranked according to the index and reported the user.