An actuation controller for a rider posture changing device of a human-powered vehicle comprises a detector and a controller. The rider posture changing device includes a first member, a second member, and an electrical actuator configured to move the second member relative to the first member. The detector is configured to detect actuation information relating to an actuation state in which the electrical actuator moves the second member relative to the first member. The controller is configured to evaluate the actuation state in accordance with the actuation information detected by the detector.