While 99.6% of all pairs of users are connected by paths with 5 degrees (6 hops), 92% are connected by only four degrees (5 hops). And as Facebook has grown over the years, representing an ever larger fraction of the global population, it has become steadily more connected. The average distance in 2008 was 5.28 hops, while now it is 4.74.

Thus, when considering even the most distant Facebook user in the Siberian tundra or the Peruvian rainforest, a friend of your friend probably knows a friend of their friend.

The study also found that people are much more closely connected to individuals in their own country.

Although this new “law” of separation applies only to Facebook itself, the number of Facebook’s active users is reportedly around 10% of the total human population today–do you think that is enough for the new law to be extrapolated to apply to all people in the world? Or do you think that the data just goes to show that “X knows Y” now means less than it did before?

The study also showed that Facebook's cumulative degree distribution is not nearly as skewed as earlier studies of social networks have suggested

]]> http://scenic.princeton.edu/network20q/blog/?feed=rss2&p=341 1 http://scenic.princeton.edu/network20q/blog/?p=208 http://scenic.princeton.edu/network20q/blog/?p=208#comments Tue, 04 Oct 2011 02:17:20 +0000 network20q http://scenic.princeton.edu/network20q/blog/?p=208 http://www.readwriteweb.com/archives/six_degrees_of_seperation_on_twitter.php

But as you’ll see in lecture on Q9, this is only half of the story, and the easier half of the story. Existence of short social chains can be easily proven for many graphs. What is hard and more useful is the searchability of short social chains, the ability of each node to use only local information to step by step find a short chain to any node. It’s more than just existence, but also (local) computability of the chain.

We’ll soon have a nugget activity to actually validate or falsify this second half of the story.

As to retwee or repost URL, which is a better measure of influence power, we’ll talk about that later too.