To provide quantitative information for determining how effective a given feature is for pattern recognition or to what extent a given feature contributed to wrong pattern recognition.

An information processing device comprises an acquisition unit that acquires a pattern of an object of processing; a feature calculating unit that calculates a feature vector representing the feature of the pattern obtained from the acquisition unit; a dictionary storing unit that stores the types of identification candidates and a set of representative vectors of the identification candidates; and an identification influence extent calculating unit that acquires from the dictionary storing unit the set of representative vectors matching the types, so performs decomposition as to match the extent of similarity or the extent of difference between the object of processing and identification candidates obtained from the set and the feature vectors with the respective components of the feature vectors, and calculates the value obtained by the decomposition as the extent of the influence of the components of the feature vectors on pattern identification.