1. An apparatus comprising: a first sensor at a first media monitoring location; a second sensor at a second media monitoring location; a central processor at a central site configured to remotely control collection of audience measurement data from the first media monitoring location and the second media monitoring location based on a variable system factor, the central processor to (a) measure the variable system factor at the central site and (b) control the first sensor at the first media monitoring location to collect a first type of data and control the second sensor at the second media monitoring location to collect a second type of data based on the variable system factor.