An information processing apparatus of the present invention acquires, from a communication device of a user, at least one of utterance information by the user and position information of the communication device, specifies a predetermined region according to a mark included in the utterance information; acquires a movement direction of the user from at least one of the utterance information and the position information acquired from the communication device of the user, and setting a probability distribution that the user exists to a divided region of the predetermined region based on the acquired movement direction of the user; and presumes the user based on the set probability distribution.