Office workers who make time to chat face to face with colleagues may be far more productive than those who rely on e-mail, the phone, or Facebook, suggests a study carried out by researchers at MIT and New York University.

The researchers outfitted workers in a Rhode Island call center with a wearable sensor pack that records details of social interactions. They discovered that those employees who had in-person conversations with coworkers throughout the day also tended to be more productive.

The results aren't yet published, but they support research published last December by the same team. This study showed that employees at an IT company who completed tasks within a tight-knit group that communicated face to face were about 30 percent more productive than those who did not communicate in a face-to-face network.

"The big idea is that what you do on your coffee break and over lunch really matters for productivity," says Sandy Pentland, a professor at MIT's Media Lab, who led the study. "Face-to-face networks matter, and the implications are huge."

Many managers probably suspect a link between personal communication and productivity, says Pentland. Conventional wisdom suggests that face-to-face conversations are a useful way to create and maintain strong social networks, which could help workers solve complex customer problems or complete more calls at the center, he says.

However, some managers are slow to implement policies that foster this sort of communication because the connection has been difficult to prove with hard data, says Pentland. Usually, he says, workplace socializing is recorded using participant surveys, which tend to be filled with errors, since it can be difficult to remember the details of social interactions.

"There's all this knowledge that you see in anthropology and sociology [studies] that doesn't make it into management because it's sort of soft data," says Pentland. "But now we can tell which sort of folk wisdom is true . . . We can put some numbers on the table."

Pentland's study used a sociometer, a device about the size of a deck of cards, which participants wear around their necks as they would an identification badge. Each sociometer contains an accelerometer to measure their movement; a microphone that picks up their speech characteristics, such as intonation and cadence; a Bluetooth radio to detect other people wearing sociometers nearby; and an infrared sensor that can detect face-to-face interactions. Worn all day, the sociometers log workers' activity and conversations.