ONE afternoon in early August, a 41-year-old working mother in Los Angeles didn’t get much work done.


Instead, she watched the London Olympics on television. She went to NBC’s Web sites to stream the competitions, which that day included badminton, beach volleyball, tennis, cycling, judo and gymnastics. She watched swimming live on her tablet and chatted with friends about the Games on Twitter and Facebook. The only time that day she was not engaged in something related to the Olympics was when she appeared to be in the car — or asleep.


She was one of more than 50,000 participants in a dozen studies conducted by Comcast’s NBCUniversal unit as part of its so-called Billion Dollar Research Lab. The research did not cost $1 billion, but NBCUniversal paid more than four times that sum in 2011 to broadcast the Olympics through 2020. As part of that giant tab, the media company gets an exceptional opportunity to study viewers’ behavior.


The findings of the studies, shared with The New York Times, revealed vast shifts in the way people watched the Games this year compared with the Olympics in Vancouver in 2010 and in Beijing in 2008, and they offered insight into how television will further evolve into a multiplatform experience.


Think of it as the world’s largest “sandbox” in which media researchers can play, said Alan Wurtzel, president of research and media development at NBCUniversal. “It gives us a glimpse into the future.”


Mr. Wurtzel, whose office at 30 Rock in Manhattan is decorated with a brick-size cellphone and an antique calculator the size of a typewriter, among other relics, walked through 60 pages of charts and statistics. He will unveil the findings to advertisers next week at the American Marketing Association conference in Las Vegas and during an event related to Advertising Week in New York.


For research wonks there’s no event quite like the Olympics. Roughly 217 million people in the United States watched the London Games, making it the most watched television event in history. And unlike other big, live events like the Super Bowl or the Academy Awards, the Olympics offer researchers a prolonged, 17-day period during which to study behavior.


That sandbox showed that eight million people downloaded NBC’s mobile apps for streaming video, and there were two billion page views across all of NBC’s Web sites and apps. Forty-six percent of 18- to 54-year-olds surveyed said they “followed the Olympics during my breaks at work,” and 73 percent said they “stayed up later than normal” to watch, according to a survey of about 800 viewers by the market research firm uSamp.


Forty-six percent said they “delayed doing laundry and other household chores” to catch events like gymnastics, where the United States inched out a win over Russia and Romania for the gold, and swimming, where Michael Phelps narrowly came in second in the men’s 200-yard butterfly.


NBC will work its Olympics lab results into its advertising sales pitch. One study measured viewers’ recollections of 56 brands. The brands advertising during the coverage, especially if the ads were in some way related to the Olympics, registered better recall. Seventy-six percent of respondents said they “enjoyed watching commercials during the Olympics that are tied in some way to the Games.”


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The results signaled vast changes from just two years ago in Vancouver, when tablets and mobile video streaming were still in their infancy. The two most streamed events on any device during the London Olympics, the women’s soccer final and women’s gymnastics, surpassed all the videos streamed during the Vancouver Olympics combined.


The growing number of viewers who own tablets will only lead to more streaming. “That’s clearly a glimpse of where tablets are going,” Mr. Wurtzel said. Thinking ahead to the Winter Olympics in Sochi, Russia, in 2014 and to the Summer Games in Rio de Janeiro in 2016, he added: “All bets will be off as the price of tablets goes down.”


But perhaps the most important results for NBC’s business interests were its findings that the deluge of online viewing options did not cannibalize the coveted prime-time audience, Mr. Wurtzel said.