From Science:
Your telephone may know more about your private life than you do, according to a new study of mobile phone calls. The insight opens the door to mining massive data sets from mobile phone call logs, which should allow researchers to test theories for how relationship networks make or break businesses, shape the flow of information, and even affect the course of epidemics.
A nagging problem for social scientists is the limitation of self-reported survey data. Not only are people expensive to poll, but they are also notoriously error-prone when they try to recall their own behaviors. What researchers would prefer is a record of people's behaviors that is cheap and accurate. Mobile phone call logs can certainly provide enormous amounts of cheap data. Researchers have used such data to map out people's social networks, utilizing the duration and frequency of calls between pairs of people as a measure of the intimacy of their relationships. Doing so has revealed patterns of people's contact with each other both in time and space, which is crucial for modeling everything from gossip to how flu viruses spread across populations.
But how accurately do call patterns reflect the intimacy of relationships? After all, sometimes the closest of friends rarely call each other, while some motor mouths call just about everyone.
More here.