An apparatus is attached to one portion of a user's body for use, and has a detection unit that detects information corresponding to motion of the user. The apparatus measures an activity amount of the user based on information detected by the detection unit and, if multiple apparatuses are attached to the user's body, transmits information to an activity identification unit that identifies an activity being performed by the user based on information detected by the detection units of the attached activity amount measuring apparatuses and information indicating the attachment portions of the attached activity amount measuring apparatuses. The transmitted information is information that is detected by the detection unit and associated with the information indicating the identified attachment portion. The activity amount is corrected based on the activity that is identified.
