Four degrees of separation

Abstract

Frigyes Karinthy, in his 1929 short story "Láncszemek" (in English, "Chains") suggested that any two persons are distanced by at most six friendship links.1 Stanley Milgram in his famous experiments challenged people to route postcards to a fixed recipient by passing them only through direct acquaintances. Milgram found that the average number of intermediaries on the path of the postcards lay between 4:4 and 5:7, depending on the sample of people chosen. We report the results of the first world-scale social-network graphdistance computations, using the entire Facebook network of active users (⇡ 721 million users, ⇡ 69 billion friendship links). The average distance we observe is 4:74, corresponding to 3:74 intermediaries or "degrees of separation", prompting the title of this paper. More generally, we study the distance distribution of Facebook and of some interesting geographic subgraphs, looking also at their evolution over time. The networks we are able to explore are almost two orders of magnitude larger than those analysed in the previous literature. We report detailed statistical metadata showing that our measurements (which rely on probabilistic algorithms) are very accurate.

Nowhere to Hide: Navigating around Privacy in Online Social Networks

“…We notice that it goes from 4 to 18 hops in Facebook, with most of shortest paths being between 9 and 11-hops long. This is around twice the distance found in [6] with the knowledge of the full social graph. The shortest paths are between 3 and 11 hops in Google+, most of them being 6 hops long.…”

“…The considered OSNs exhibit power-law degree distributions, a densely connected core of high-degree nodes linking small groups of strongly clustered nodes and, as a result, short path lengths. A crucial step in providing evidence about the small-world characteristics of OSNs has recently been achieved with the publication of two reports by Facebook researchers on the Facebook full social graph [6,39]. Their dataset of 721 million users shows the main small-world properties: 99.91% users belong to the largest component, the distribution of nodes degree follows a power-law distribution, and the average distance between users equals 4.7, showing that OSNs are even smaller than real-world social networks.…”

The geography of the iWiW

“…Definíció szerint az online közösségi hálózatok (online social networks: OSN) az internetalapú kommunikáció termékei, segítségükkel dokumentálhatók és könnyen fenntarthatók a kapcsolataink olyan személyekkel, akikkel korábban személyesen is találkoztunk (Boyd-Ellison 2007). Az online közösségi hálózatok -fokszámeloszlásukat tekintve -hasonlóak az offline közösségi hálózatokhoz (Boyd-Ellison 2007, Ahn et al 2007, Backstrom 2012, Ugander et al 2011. Ugyanakkor van egy alapvető különbség e hálózatok között: a felhasználók nem képesek minden barátjukkal erős kapcsolatot fenntartani OSN-kör-nyezetben.…”

Computational Method for Supporting Learning with Cumulative Vocabularies, Conceptual Networks and Wikipedia Linkage

“…According to an experiment of full hyperlink network of the Wikipedia on 3 March 2008 [27] on average 4,573 traversals of hyperlinks are needed to get from any article to any other article. Correspondingly in a mailing experiment in the USA with 296 persons the number of relationship steps connecting two persons was in the range 4,6-6,1 [28], and in Facebook social network with 721 million users and 68,7 billion links between them the average number of relationship steps was 4,74 [29].…”