review articles

Doi: 10.1145/1400214.1400232

Internet-based data on human interaction connects scientific inquiry like never before.

BY Jon KLeinBeRG
the
convergence
of social and
technological
networks

The past decade has witnessed a coming-together of the technological networks that connect computers on the Internet and the social networks that have linked humans for millennia. Beyond the artifacts that have sprung from this development—sites such as facebook, LinkedIn, MySpace, Wikipedia, digg, del. icio.us, You Tube, and flickr—there is a broader process at work, a growing pattern of movement through online spaces to form connections with others, build virtual communities, and engage in self-expression.

Even as these new media have led to changes in our styles of communication, they have also remained governed by longstanding principles of human social

interaction—principles that can now be observed and quantified at unprecedented levels of scale and resolution through the data being generated by these online worlds. Like time-lapse video or photographs through a microscope, these images of social networks offer glimpses of everyday life from an unconventional vantage point— images depicting phenomena such as the flow of information through an organization or the disintegration of a social group into rival factions. Science advances whenever we can take something that was once invisible and make it visible; and this is now taking place with regard to social networks and social processes.

Collecting social-network data has traditionally been hard work, requiring extensive contact with the group of people being studied; and, given the practical considerations, research efforts have generally been limited to groups of tens to hundreds of individuals. Social interaction in online settings, on the other hand, leaves extensive digital traces by its very nature. At the scales of tens of millions of individuals and minute-by-minute time granularity, we can replay and watch the ways in which people seek out connections and form friendships on a site like Facebook or how they coordinate with each other and engage in creative expression on sites like Wikipedia and flickr. We can observe a news story suddenly catching the attention of millions of readers or witness how looming clouds of controversy gather around a community of bloggers. These are part of the ephemeral dynamics of ordinary life, now made visible through their online manifestations. As such, we are witnessing a revolution in the measurement of collective human

The Nexus friend grapher application, created by Ivan Kozik, allows Facebook account holders to generate graphs illustrating their social network of friends. The resulting spheres not only demonstrate how friends are connected, but also indicate the interests shared by different groups of friends. For more information, or to create a graph, visit http://nexus.ludios.net.