We may not be 6 degrees apart

In class we talked about friend-of-a-friend networks and how everyone is supposedly only six degrees of separation away from everyone else. It turns out that Milgram's famous small world experiment didn't actually have the incredible results that we commonly associate with it.

The experiment gave envelopes to people in Kansas with the name of a target person and several details about that person's life. Participants were asked to pass the envelope on to someone they knew who could get it closer to the target. Some of the stories sound pretty amazing:

"...an envelope that made its way from a wheat farmer in Kansas to the target, a divinity student’s wife in Cambridge, Massachusetts, with just two connections."

This recent article from Discover Magazine discusses some of the limitations of Milgram's experiment. The studies had a completion rate of only 5-30%. Judith Kleinfeld's paper, "Could it be a big world after all?", describes how after extensive research Kleinfeld found only two replications of Milgram's work, which is pretty low for something so universally accepted as truth. Another draw back with the chain-mail approach of the original is that because participants can't see the entire network, they may inadvertently send the letter further away from the target.

With the popularity of social networking sites comes the opportunities to further research the idea of six-degrees of separation. Many of the drawbacks of Milgram's experiment could be eliminated. Researchers looking at the data from social networking sites can see the entire social network and find the shortest path. Completion rates aren't an issue if computers are tracing the connections. One example, LiveJournal Connect, tries to find a path between two LiveJournal users. You could probably get some pretty interesting results with something similar on Facebook.