• by David Goetzl  @dgoetzl, December 6, 2011

As Viacom began expressing doubts about major drops in Nielsen ratings at Nickelodeon, CEO Philippe Dauman cited an alternate ratings source, set-top-box data, as evidence of possible under-counting. A comparison between Nielsen and that information shows Nickelodeon may be doing better than the Nielsen tracking, notably in two key dayparts: weekday afternoons and weekend mornings.

That’s not to say Nick couldn't benefit from some reinvigorated programming or an infusion from “Kung-Fu Panda," but young people might not be turning to their parents' iPhones or other viewing devices as much as some numbers suggest.

For October, set-top-box (STB) data provider Rentrak shows Nickelodeon ratings declined 1% on weekday afternoons (2 p.m. to 8 p.m.), while Nielsen has the drop at 14%.

Also, Rentrak shows ratings for Saturday and Sunday mornings (8 a.m. to 12 p.m.) actually increased 5%. Nielsen recorded a 10% drop.

“You're seeing pretty big swings between the two data sets," said Peter Sedlarcik, a senior vice president in research at MPG. "It kind of makes you say, 'OK there's something not exactly lined up here, what's going on?'”

The October 2010 vs. 2011 comparisons measure households with kids, looking for apples-to-apples comparison between Nielsen and Rentrak. The figures come from the Collaborative Alliance, an industry initiative looking to improve measurement, which does not take positions on the benefits of one data source over another. 

The Nielsen ratings drops have been a drag on Nick revenues, particularly coming with the holiday season approaching. Nielsen stands by its Nick data and says there has been no change in its methodology, which would contribute to year-over-year declines.

The Rentrak data also varies notably for a weekday daytime block (9 a.m. to 2 p.m.) -- a time period when Nick offers “Max and Ruby” and “Dora the Explorer.” Rentrak shows a 9% drop, while Nielsen doubles that at 18%.

The Collaborative Alliance also pulled numbers from TiVo, which has STB-based measurement products. For September (5 a.m. to 9 p.m.), Nick ratings fell 6.2% among households with kids ages 2 to 17. Nielsen shows a 10% decline for similar time periods, though that does not mark an apples-to-apples comparison. 

The Collaborative Alliance reached out to Kantar, which culls STB data from DirecTV homes, but it declined to provide data.

The difference between the Nielsen and STB numbers is part of the file the Media Rating Council (MRC) is using to investigate the Viacom-Nielsen dispute. One intriguing dynamic: the MRC is looking at the stability of STB data, but it has not given it accreditation.

Depending on the MRC's ruling, it is possible that the independent third party may find itself with more work on its hands. If a ruling favors Viacom, networks questioning Nielsen results because STB data paints a different picture may also petition for relief.

“The benefit of having it is to be able to take a second and third look at things when the numbers from Nielsen aren't what we would expect or within what we would expect to be reasonable fluctuations,” MPG's Sedlarcik said.

Rentrak culls STB data from a variety of sources including Dish Network and AT&T, while Nielsen relies on its panel-based system. Rentrak and others in the STB space argue their numbers are more representative since they are drawn from more homes than Nielsen uses.

Even if the Nielsen numbers showing Nickelodeon declines are spot-on, Sedlarcik said it’s a bit early to make a “huge cultural statement” about changing viewing behavior. There will need to be more monitoring in the coming months.

Who knows if that will yield any conclusions? After all, one combined October average for kids’ networks -- Nick, Disney Channel, Cartoon Network, etc. -- has Nielsen showing a 5% decline.

Rentrak? A 1% increase.