A New TV Ratings Method: Bag Sample, Take Census

Have you ever wondered how Nielsen Media Research can determine how much TV the entire country watches by monitoring the viewing habits of just a tiny fraction of households nationwide?

For decades, that is how the audience measurement company has calculated the ratings for the 200 million-plus viewers in the U.S. And Nielsen’s approach to ratings measurement has been, and continues to be, the subject of criticism. But now, one critic—and potential competitor—charges that Nielsen’s entire methodology (so-called “random sampling”) is completely ineffective for measuring channels in the fragmented digital era.

For big broadcast and cable networks like CBS, NBC, ESPN and Lifetime, which attract audiences in the millions or at least hundreds of thousands, Nielsen’s sampling methodology is statistically valid, according to TV network and ad agency researchers.