Then what of my example? Household, er, dwelling unit in a PPM market -- say, Pittsburgh -- is selected to participate in the Nielsens and all occupants thereof are given their meters and instructions on what they're supposed to do with them. At the time the "unit" is selected, all four occupants are residents of Pittsburgh. Three months into Nielsen participation, though, big brother is accepted to Harvard and heads off to Massachusetts three months after that, stays there for the next six months -- minus holiday vacation -- then comes home for the summer. My question is simple, and one that you did not answer directly: Does big brother take his PPM to Cambridge and have his listening to WBOS, WXLO or whatever else he listens to there count in the Boston ratings? Or does big brother's leaving the Steel City for the Hub of the Universe to further his education immediately disqualify his entire family from Nielsen participation and everybody turns in their meters and slinks off in total disgrace and shame?