Methods, apparatus, and systems to collect audience measurement data are disclosed. An example system includes at least one non-transitory machine readable storage medium including instructions which, when executed, cause a machine to at least: generate behavior data developed during a first time period based on first media data and user data corresponding to one or more users of a household, the user data to include demographic information for the one or more users associated with the household, identify second media data during a second time period different than the first time period, the second media data identified without identification of the one or more users of the household, and associate the demographic information to the second media data based on the behavior data generated during the first time period associated with the one or more users.