An information processing apparatus includes a specification unit that specifies a duration expected such that a predetermined activity has been performed based on sensor data indicating a motion of at least one region of a body in time series; a detection unit that detects a motion group in the duration based on the sensor data; and a calculation unit that calculates, based on a feature of a detected motion group, a likelihood that the motion group is the predetermined activity. Accordingly, the activity duration may be correctly detected when the way of movement varies in accordance with the subject, the surrounding environment of the subject, or the state of the subject.