A specifying method executed by a processor, the specifying method includes specifying a first period for which it is determined that a specific movement or a specific posture is being performed by applying a first threshold to time series data obtained from a sensor for detecting a movement of a person, specifying a second period for which it is determined that the specific movement or the specific posture is being performed by applying a second threshold to the time series data, the second threshold being eased compared to the first threshold, and specifying a transitional period based on a difference between the second period and the first period, the transitional period corresponding to one of a period of a transition to the specific movement or the specific posture, and another period of another transition from the specific movement or the specific posture to another movement or another posture.