>Each person in the world (at least among the 1.59 billion people active on Facebook) is connected to every other person by an average of three and a half other people.<p>This is a big deal, and always a fascinating result, but the other 5.5 billion cannot be merely discounted. 1.6 billion is over 22% of the global population, which makes for a very good sample set, but it is definitely biased. I may be 3.3 degrees away from "everyone on Facebook" but that isn't everyone. Almost by definition, those 5.5 billion people not on Facebook should be harder to reach, requiring many more steps.<p>Results from Weibo would be an interesting comparison.
This number is pretty deceiving. The degree of separation is meaningful only if you can actually leverage your relationship to pass on the message in the graph. In FB graph, I would think that vast number of relationships are not mutual, active or "leveragible".<p>Here's better way to find degrees of separation:<p>Assign each relationship some weight. For example, if two people haven't interacted mutually with each other than weight is much higher and vice versa. Now compute all pairs shortest path and take average. This would give a much better picture of actual degree of separation.
Reminds me of how NSA uses 3 degrees to target your communications: <a href="http://www.theguardian.com/world/interactive/2013/oct/28/nsa-files-decoded-hops" rel="nofollow">http://www.theguardian.com/world/interactive/2013/oct/28/nsa...</a>
Why is Facebook confusing the EVERYBODY connected within X steps with AVERAGE connection distance?<p>Are they deliberately lying, or incompetent?<p>6 degrees hasn't shrunk. Facebook is merely counting something else. Why doesn't anyone point this out? I feel like I'm taking crazy pills.
I already know how I'm connected to the big Z, and amusingly enough it is close to their 3.5 degrees of separation. My ex-girlfriend (1) has an aunt (2) that has a cousin who is Priscilla (3) who is wife of Z (4).<p>We'll meet someday Z! I just have to patch up things with my ex..
The original question wasn't the average separation, it was the number of degrees to connect everybody. Looking at that distribution graph it looks like 6 is about right. To some significance anyways, I'm sure the distribution tail goes on for a ways.
It'd be super interesting to see degrees of separation within particular communities. e.g. I live in a college town with a population of about 65,000, something like 25,000 of those are college students and "don't count" due to their transient nature. As a result, it seems like everyone knows everyone here, despite the 40,000 non-transient population. I'd guess at somewhere around 2 - 2.5 degrees, but it'd be interesting to know the actual.
Cool, but a more meaningful number concerning the original meaning of "six degrees of separation" than the average of the average of the degrees of separation between each individual and everyone else would be the average of the average of the 90th, 95th, 99th etc percentiles of the degrees of separation between each individual and the most distantly separated other individuals in the graph (maybe excluding outliers who only have a few Facebook friends).
Alright, here's where I need people strong in statistics to correct me if I'm wrong as I learned it a while back. If I'm right, then this is another misuse of math to push some BS result. If I'm wrong, then it's meaningful in some way maybe. So, here is two claims about averages:<p>1. The average of a diverse group means something for an individual. Like in this article where they connect individuals to average degree of separation.<p>2. Averages, due to their nature, don't mean anything for an individual. They're mainly good for identifying and tracking trends. So, no connection could be made here.<p>A pro told me that No 2 is the case a long time ago. It made more sense given the data I've looked at as well in terms of example problems and reports. Need more peer review on that as statistics is kind of opinionated on how its applied. If No 2 is true, then this report is more BS that's too common and the comments here become really amusing (or sad if one is an education reformer).
Reminds me of a thing we worked on some time ago:<p><a href="http://blog.stephenwolfram.com/2013/04/data-science-of-the-facebook-world/" rel="nofollow">http://blog.stephenwolfram.com/2013/04/data-science-of-the-f...</a><p>Unfortunately the degrees of separation is not something we could ever have computed with the limited data we had.
I've always been curious about facebook scaled their "people you may know feature". Everything I've read suggests that they use contact list information uploaded by other users to introduce connections in the social graph. What I'm curious about is how they compute the intersection of the large sets that result, for a lot of people, in real time.
How does this work if the graph isn't connected? Like if there are people who are only friends with each other and no one outside their group. Surely out of a billion people, there must be some people like that on facebook.
> In our implementation, at each step each person sends a bitwise ORed hash value to all his friends.<p>I didn't follow how ORing the hash is supposed to work or what it is meant to do. Anyone know?