Sunday, September 11, 2005

Expected-value Navigation

Researchers at UMass-Amherst announced this week that they've derived an algorithm useful for explaining the "six degrees" phenomenon in social networks (and related activity systems) (via). 

The social network exploited by Travers and Milgram isn't a straightforward, evenly patterned web. For one thing, network topology is only known locally—individuals starting with the letter did not know the target individual—and the network is decentralized—it didn't use a formal hub such as the post office. If navigating such a network is to succeed—and tasks such as searching peer-to-peer file sharing systems or the navigating the Web by jumping from link to link do just that—there must be parts of the underlying structure that successfully guide the search, argue Jensen and Şimşek.

What guides the search?  The press release briefly touches on issues of homophily and "degree disparity." Previous research has tended to treat these qualities discretely, Jensen and Şimşek's algorithm merges or blends them. Perhaps most noteworthy from the release is the question of how network topologies are known. This hooks into a few of the talks from CCR Community Day '05 and also at least a couple of the motivations behind CCC Online: how is disciplinarity known?

Posted by Derek Mueller at September 11, 2005 8:00 AM to Networks