Patent attributes
A system includes: a preference model generating unit that generates a preference model by learning and storing the preference model for a user based on a behavior history that indicates history of behavior of the user; an evaluation list generating unit that calculates probability of a plurality of recommended candidates based on the preference model and generates an evaluation list indicating the probability of the recommended candidates; a default predicting unit that specifies habituation of the user based on the information on the behavior history and calculates a predicted default value of the plurality of recommended candidates based on the habituation; and an evaluated unexpectedness value calculating unit that calculates an evaluated unexpectedness value indicating unexpectedness where the unexpectedness is higher as a difference obtained by subtracting the predicted default value from the probability is larger.