image: Sharing a graduation year, rather than other factors, drives online social networks for college graduates. view more
Credit: North Carolina State University
Are you connected to college friends on Facebook? Research from North Carolina State University shows that these social networks tend to form around graduation year or university housing – rather than other interests.
Researchers examined the first 100 colleges and universities to have students, faculty or staff join Facebook when the site exclusively contained .edu email addresses. As students, faculty and staff joined Facebook, social networks were formed. Each university, in essence, formed its own network – ranging in size from 762 to 50,000.
"We wanted to see what defining characteristics grouped people together within these networks," says Amanda Traud, a Ph.D. student in biomathematics at NC State and lead author of a paper describing the study. The social networks studied in this case included all of the users and their Facebook friends from these schools in September 2005. The data was given to the researchers by Adam D'Angelo of Facebook.
The researchers used community detection techniques to identify groups within each network. A community was defined as a group in which individuals were more connected to each other than to the rest of the network. The researchers then used statistical tools to determine what characteristics dominated each group.
"We found that most groups were largely composed of people with the same graduation year, though some groups were composed of people who lived in the same university housing," Traud says. "I found it interesting that the subject people majored in and where people went to high school played little to no role in the social structure."
The university networks that had groups dominated by housing also tended to have smaller residence halls, or halls in which students lived for more than one year.
"This indicates that universities can contribute to creating a strong sense of community among students by manipulating their student housing efforts," Traud says. "In the absence of these efforts, graduation year seems to be the default."
The paper, "Social structure of Facebook networks," was co-authored by Dr. Peter Mucha at the University of North Carolina-Chapel Hill and Dr. Mason Porter of the University of Oxford. The paper is published online in the journal Physica A. The research was supported by the National Science Foundation, the UNC ECHO program and the James S. McDonnell Foundation.