o (via Mobile data show friend networks by the BBC.) The researchers were able to guess from the mobile data alone, with 95% accuracy, if any given pair of users were friends. An analysis of the overall proximity of a given user to his or her friends - maximised if they worked together - was correlated to people who reported a high level of satisfaction at work. And “For people who said that a given individual was a friend, they dramatically overestimated the amount of time they spent. But for people who were not friends, they dramatically underestimated that amount of time.”
o (via Mobile data show friend networks by the BBC.)

The researchers were able to guess from the mobile data alone, with 95% accuracy, if any given pair of users were friends.

An analysis of the overall proximity of a given user to his or her friends - maximised if they worked together - was correlated to people who reported a high level of satisfaction at work.

And

“For people who said that a given individual was a friend, they dramatically overestimated the amount of time they spent. But for people who were not friends, they dramatically underestimated that amount of time.”