In a control method, a vibration sensor of an information terminal apparatus acquires vibration data that is time-sequential data of vibrations including vibrations based upon body movements of a user on bedding on which the information terminal apparatus is placed. The acquired vibration data is stored in a memory, an action performed by the user is detected, and, from among the vibration data stored in the memory, vibration data included in a predetermined period that ends at a time at which the detected action was performed is extracted. Then, a vibration waveform indicated by the extracted vibration data is stored in the memory as a bed-leaving vibration pattern produced by the user.