Nielsen said that a software update resulted in some viewing data on broadcast and syndicated shows being attributed to the wrong network.
The error seems to have mainly been in ABC’s favor, according to industry sources. When revised numbers are released, ABC’s are expected to be lower and the other networks’ are expected to rise.
Nielsen, in a press briefing Friday, said the problem occurred in March, but was imperceptible until the beginning of the new fall season when viewing levels rose. The issue was corrected Oct. 6, Nielsen said.
Ratings will be restated as of the beginning of Aug. 18, but Nielsen global president Steve Hasker said that 98.5% of all shows were affected by less than 0.05% of a ratings point.
So far this season, ratings of shows on ABC have been seeing unusually large increases from their fast national ratings to the final live plus same day number.
The season premieres of Once Upon A Time and Resurrection both rose 0.3 percentage points.
Nielsen declined to comment when asked whether the issue resulted in increased viewing being attributed mainly to ABC. Nielsen said updated ratings have been sent to the networks and will be released publicly on Monday.
David Poltrack, chief research officer at CBS, said it was clear that ABC benefited from the error.
“That’s pretty clear to anyone who’s been looking at the ratings,” he said. How big is the issue? “It’s certainly significant for ABC,” he said. “It’s of lesser significance to the rest of us.”
Poltrack said that when the new numbers come out, in cases where ABC shows added three or four tenths of a percentage point, three of three of those will likely go away.
Gains for the other networks will be smaller. “It’s still nice to have one of these controversies where you benefit.”
ABC would not provide information about how the glitch affected its ratings.
“Our entire industry relies upon Nielsen for accuracy and veracity, and we hope that they can quickly resolve this issue,” an ABC spokesman said. “We’re confident that the momentum we’ve seen across the network so far this season will continue, including delivery of the No. 1 new drama and the No. 1 new comedy on television.”
CBS’ Poltrack said that he’d have preferred that CBS hadn’t needed to bring the issue to Nielsen’s attention before Nielsen acknowledged there was an issue.
“That’s always a concern,” he said. He said he was looking for Nielsen to set up a policy change that creates a review process that prevents this from happening in the future.
When there are unusual changes in the ratings “that should set off alarm bells that something went awry," Poltrack said.
Nielsen has not issued C3 ratings for this season yet, so make goods are not an issue for this season, senior VP planning policy and analysis Patricia McDonough said.
The issue is separate from concerns that ratings for all broadcast and cable networks are moving lower because Nielsen has included more broadband only homes, decreasing the people using television count.
Hasker also took some shots at rival ratings service Rentrak, which was in the news for making a deal with WPP and its GroupM media buying unit. Hasker’s remarks were originally on background, but were put on the record when some reporters on the conference call protested.
“Rentrak never lets the fact get in the way of a good press release,” Hasker said. He noted that a recent announcement indicated media agency Zenith would use Rentrak numbers for currency. Later the agency said it would only be testing Rentrak’s data.
Hasker said Rentrak does not use “census” data, and the Media Rating Council has asked Rentrak to stop using that description.
“We believe their measure only about 40% of the households in America,” he said. “It is not currency data.”
Rentrak CEO Bill Livek refuted Nielsen's claims, and said he thought the timing of Nielsen's jabs was odd.