DATA CLASSIFICATION DEVICE, DATA CLASSIFICATION METHOD, AND DATA CLASSIFICATION PROGRAM

A data classification device includes: a known data input unit that receives an input of known data, the known data being data already classified into a class and a subclass subordinate to the class; a feature extraction unit that extracts, from features included in the known data, a feature that causes classification of the known data belonging to the same class into a subclass using the feature to fail; and a classification unit that classifies classification target data into a class using the feature extracted by the feature extraction unit.