Methods and systems for conserving power using predictive models and signaling are described. Parameters of a power management policy are set based on predictions based on user activity and/or signals received from a remote computer which define a user preference. In an embodiment, the power management policy involves putting the computer into a sleep state and periodically waking it up. On waking, the computer determines whether to remain awake or to return to the sleep state dependent upon the output of a predictive model or signals that encode whether a remote user has requested that computer remain awake. Before returning to the sleep state, a wake-up timer is set and this timer triggers the computer to subsequently wake-up. The length of time that the timer is set to may depend on factors such as the request from the remote user, context sensors and usage data.