The Ratings Mirage: Why Fox has higher ratings--when CNN has more viewers

[rpannier]

I found this article and I think it's very informative.

After exposure to countless similar stories published since January 2002, when Fox was reported to have surpassed CNN in the Nielsen ratings, one might naturally conclude that Fox has more viewers than CNN.But it's not true. On any given day, more people typically tune to CNN than to Fox.

So what are the media reports talking about? With few exceptions, stories about the media business report a single number for ratings (often expressed two different ways--as "points" or "share"). This number is often presented as if it were the result of a popularity contest or a democratic vote. But it is actually the average number of viewers watching a station or a show in a typical minute, based on Nielsen Media Research's monitoring of thousands of households.

But there is another important number collected by Nielsen (though only made available to the firm's clients) that tells another story. This is the "cume," the cumulative total number of viewers who watch a channel for at least six minutes during a given day. Unlike the average ratings number the media usually report, this number gives the same weight to the light viewer, who tunes in for a brief time, as it does to the heavy viewer.

Journalists who publish Nielsen numbers ought to explain that the data are not simply measures of popularity, and they are not produced as a service to journalists or the public. The figures are gathered to provide advertisers with complex data about viewer habits. It pays to remember that neither cable news stations nor Nielsen Media Research are primarily in the business of serving the public interest--both are in the business of delivering audiences to advertisers.

The full article can be found at:
http://www.fair.org/index.php?page=2005