During the recently concluded November ratings sweeps, syndicated reruns of "The A-Team" on KHJ-TV Channel 9 were the most-watched television show in Los Angeles between 6:30 and 7 p.m., beating everything from old "Family Ties" episodes to Dan Rather and the evening news.
It was, that is, in the Arbitron ratings.
In the ratings survey from the A.C. Nielsen Co., "The A-Team" was dead last among the seven most prominent local stations. KTTV Channel 11's "Family Ties" was No. 1.
This conflict over the current popularity of Mr. T and his gang was only the most glaring discrepancy between the two ratings services for the November sweeps that ended last week. Two different winners were produced again in the local news race: KABC-TV Channel 7 in Arbitron and KNBC-TV Channel 4 in Nielsen.
Depending on who you talk to, these variations between the two reports, which purport to measure the viewing habits of the same 4.8 million households over the same four weeks through a survey of 500 homes, are either nothing to be alarmed at, terribly confusing or symptomatic of how inadequate and inaccurate both ratings services are.
"With the diversity of the L.A. market, you just can't do justice to a population of this size," said Felix Gutierrez, a journalism professor at USC who teaches graduate courses in survey research. "If you're trying to divide such a small sample between different age, racial, lifestyle and language groups, each sample household within each segment of the population carries more weight than it should. If one Hispanic changes the channel, it's like 300,000 just did."
While advertisers, station executives and even representatives of the two ratings services agree that the current measuring system is anything but an exact science, however, no one seems willing to dismiss it entirely. It is, they all say, the only game in town for gauging how many people are watching a particular program and determining how much advertisers should pay for a commercial on the program.
"You could never put a man on the moon with this kind of research," said Elaine Kaplan, senior vice president of Western International Media, the No. 1 buyer of advertising time in Los Angeles. "But you create your own monster, and now you have to live with it."
Indeed, six of the seven major commercial stations in Los Angeles subscribe to both services. KNBC-TV Channel 4, which for years has been rated lower by Arbitron than by Nielsen, discontinued using Arbitron numbers two years ago and refused to renew its subscription with the company last October, saving the station approximately $1 million a year, according to John Rohrbeck, Channel 4's general manager.
The real problem with the current ratings system, said Terry Pittman, research director at KCBS-TV Channel 2, is that many of those who use the numbers try to push them beyond what they are designed to do. In their quest to be able to promote themselves as No. 1, stations crunch the numbers down to a tenth of a point--when the fact is, he said, that the margin for error in these surveys is generally one rating point.
For example, in the 4 p.m. time period last month, the Nielsen ratings showed Channel 4 on top with a 7.2 rating, while Channel 2's "Geraldo" and the Channel 7 news tied for second with a 6.6 mark. A clear victory for Channel 4? Not really.
Ratings experts said that because of the margin for error, 7.2 and 6.6 are essentially the same number. In their final books, both Arbitron and Nielsen round off their ratings and would report all three as 7 (each local rating point represents 48,002 homes).
Advertisers, Kaplan said, usually round the numbers down, in this case to a 6, when considering where to place their ads and how much they are willing to pay.
Still, none of that explains why Channel 4 does significantly better in Nielsen or why "The A-Team" is rated nearly twice as high by Arbitron.
Executives from both Nielsen and Arbitron insist that the techniques they use to gather their ratings data are scientifically sound, and both are confident that their results are "absolutely correct." Both use samples of approximately 500 households, both claim that every household in the area has an equal chance of being selected, and both insist that their samples properly represent the diversity of the market.
The easiest explanation for the discrepancies between the two is simply that each monitors a different set of 500 homes. Roy Anderson, executive vice president at Nielsen, said that if Nielsen monitored two sets of homes using the exact same methodology, it would come up with two different sets of results.
But there are some differences in methodology that might explain the difference in the results, according to Bill Shafer, Arbitron's vice president of television sales. Nielsen monitors its sample of homes and simply reports the data as it has been collected. Arbitron gives differing weights to certain households depending upon the demographic makeup of its reporting sample.