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.