CPS 49: The Global Commons
Cooperation and Conflict on the Internet
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Social Networks

This page is for the Jeff Forbes session on Social Networks on November 16.

Back in 1960s, Stanley Milgram gave letters to randomly chosen residents of Omaha, Neb., and asked them to deliver the letters to people in Massachusetts by passing them from one person to another. The average number of steps turned out to be about six, giving rise to the popular notion of "six degrees of separation," and eventually the "six degrees of Kevin Bacon" game in which actors are connected by their movie appearances with other actors. Consider the problem of finding how many people are within some number of steps from you in Facebook. If you are not on Facebook, you can use the Internet Movie Database or real life social networks instead.

How do you think your answer would differ if you were at UNC? Would it be different if you were at a small liberal arts school like Middlebury College in Vermont (~2,350 students)?


The class had a far-ranging discussion on the different types of networks, Facebook, and some discussion of collaborative filtering.

The notes are available in PPT.

Dr. Forbes demoed his Scrobbler system, which hooks into Facebook and lets you see what music your friends have listened to recently and do various searches.