A computer system for determining TV viewership information for one or more TV panelists is provided, the computer system having memory to store programs and one or more processors for executing the one or more programs. The programs include instructions for: receiving TV broadcast information from a TV metering device, wherein the TV broadcast information identifies a current status of a TV in a household and an associated timestamp; receiving TV panelist status information from a first login/logout device that is different from the TV metering device, wherein the TV panelist status information identifies a viewership status of the TV panelist and an associated timestamp; and correlating the TV broadcast information with the TV panelist status information in accordance with their respective timestamps to determine a relationship between the TV panelist and a respective TV program currently broadcasted by the TV in the household.