The broadcast networks were understandably freaked out by the findings of the first few weeks of the season that viewership among young people was down, especially among young men 18-34. 

   The question: Where could they have gone?
   It couldn't just be the lack of new-season hits, went the thinking among the networks, though this part of the season typically shows volatility because of all the new fall series premieres, baseball playoffs and weather changes around the country.
   So of course, the thinking continued, it must be something wrong with the data itself, as gathered and presented by Nielsen Media Research.
    The falloff is significant. According to ABC research from Nielsen data, viewership among men 18 to 34 and teens were off 8 percent and 5 percent respectively overall for broadcast and cable networks versus year-ago levels.
   The networks called Nielsen. But so far at least, Nielsen has found nothing in the data to suggest that it could be anything other than viewer falloff.
   But the research group will not know for sure until it looks at the full data from the most recent month, October, to compare it to others.
    Nielsen had been hearing rumblings about the problem as early as August, and it has been looking into it since then, with an eye especially to certain groups showing marked declines.
   "This change is particularly noticeable among younger viewers, and more prominent among younger males,” according to a statement by Nielsen on Friday.

   The research firm said it immediately initiated various analyses to get to the causes of these viewing changes. 
   For one thing, Nielsen said, it started looking at whether its weighting procedure might be a significant factor.
   Nielsen also has been checking whether its sample composition or cooperation levels might be creating a skew to older viewers or whether its data processing systems might be calculating incorrectly.

    So far, Nielsen said, it has determined that its weighting procedure and its data processing systems are not to blame for the current slippage in TV viewership and that its sample quality is at an all-time high.

    In the process, media buyers and planners have been hearing lots of buzz on the topic.

    “I have heard a number of times that the networks are questioning Nielsen on not only the sample but on the variance in the local market to national number translation,” says Harry Keeshan, executive vice president and director of national broadcast at Omnicom Group’s PHD USA.

  Campbell-Mithun director of broadcast negotiations John Rash says that the dropoff could have deeper roots.

   “This is the first generation with remote control and cable as a birthright, and the new fall season does not have the same relevance and resonance with many younger men, who are choosing other media forms or other programs than traditional network primetime,” he says.

    A CBS spokesman on Friday dismissed viewer flight as a cause, noting that its primetime viewership is virtually even with year-ago levels, despite strong postseason baseball numbers and the new Nielsen weighting.

    CBS executive vice president of research and planning David Poltrack says that the viewing slump seems concentrated among men 18-34, particularly among those 18-20 and 25-34.

    Nielsen, he says, has found declines in that demo within its unified sample, meaning the same people who were in its sample a year ago. Still, no one will have a real handle on an explanation until after the October local demographic ratings reports come out. 

    “We’re now questioning whether this is a short-term phenomenon or an aberration,” Poltrack says.

    Although there are concerns about missing audience segments, there are no fears in the ad community about losing money as a result.

    “We have guarantees in place and the networks are supplying us with the appropriate makegoods,” Keeshan says.

     “Other media forms that experienced an explosion of choice – recorded music, radio, print, the internet – have resulted in audience atomization,” Rash says. “So the fragmentation of TV audiences is an expected occurrence.