Friendship networks revealed by cell phone data.

Lazer and colleagues have compared data gathered through self-reporting versus data gathered through cell phone usage to determine whether such information can prove reliable in predicting friendships and job satisfaction. The study followed 94 subjects over the course of nine months.

Data collected from mobile phones have the potential to provide insight into the relational dynamics of individuals. This paper compares observational data from mobile phones with standard self-report survey data. We find that the information from these two data sources is overlapping but distinct. For example, self-reports of physical proximity deviate from mobile phone records depending on the recency and salience of the interactions. We also demonstrate that it is possible to accurately infer 95% of friendships based on the observational data alone, where friend dyads demonstrate distinctive temporal and spatial patterns in their physical proximity and calling patterns. These behavioral patterns, in turn, allow the prediction of individual-level outcomes such as job satisfaction.