The present invention provides information useful to various users engaged in real estate transactions. Provided is an information processing device provided with : an appraisal calculation unit that calculates an appraisal value for a real estate property using a function that differs depending on the location of the real estate property and contains evaluation factors for the real estate property as variables; an appropriate price calculation unit that calculates an appropriate price for the real estate property on the basis of the appraisal value; an assessment creation unit that creates an assessment of the real estate property containing the appropriate price; and a display control unit that displays the assessment at a client device.