Adam D.I. Kramer, Facebook Data Scientist

Social psychologist Adam D.I. Kramer, PhD, has an enviable subject pool: the world's roughly 500 million Facebook users.

As a scientist for the company, his data start with every status update, comment and "like" they generate. Each month, that adds up to 300 billion pieces of data that Kramer can use to look at a particular website feature such as the news feed, or trend such as how people can "catch" a good or bad mood from their friends. "It feels real, and somehow more legitimate than studies done on, for example, a couple hundred university freshmen," he says.

• His status: Kramer is studying Facebook "groups," the feature that allows users to create private shared spaces for family members, clients or colleagues. He's tracking what type of groups are coming together and why certain groups are more active than others. "Whenever you release a product on the Internet, you only have half a clue how it's actually going to be used by the world," says Kramer.

• A typical day: Like all employees at Facebook headquarters in the Stanford Research Park in Palo Alto, Calif., Kramer sits at a desk out in the open with no walls. The facility is filled with colorful lounge areas and "micro-kitchens" where he and other staffers can bounce ideas off one another or seek input on a project as they take breaks or grab a snack. "Meetings are half-scheduled, half-spontaneous," says Kramer. Often great ideas are born "when someone walks by someone else's desk."

• A good fit: Kramer studied logic at Carnegie Mellon University before earning his social psychology doctorate at the University of Oregon, where he studied decision-making with Sara Hodges, PhD. Friends from Carnegie Mellon led him to an internship at Google, which led to another, and then two internships at Facebook. The company hired him as a contractor in between internships and full time in July 2010. The projects he works on tap both his computer programming and psychology skills, particularly his expertise in user-level statistics, psychometrics and survey methods.

• Why he's a fan: Facebook's progressive approach to work-life balance makes it a great place to work, says Kramer. He gets free transportation and lunch every day, and the company encourages him to conduct and publish his own research on company time. He's also energized by his colleagues. "Everyone here is really smart, really motivated and wants to work here," he says.

• The big, big picture: While Kramer can't discuss many of his research projects for Facebook, one innovation he developed and published about is the "Gross National Happiness Graph," which measures the use of positive and negative words in people's Facebook status updates to the news feed over time, and aggregates them by country. Any visitor to the graph can observe how a whole country is responding to a specific event, such as a natural disaster, World Cup win or holiday. "Valentine's Day is not really as great as you would think," he says. "People who don't have anybody can be pretty negative."

—J. Chamberlin