Bursts, Cascades, and Hot Spots: A Glimpse of Some On-Line Social Phenomena at Global Scales Jon Kleinberg Cornell University As an increasing amount of social interaction moves on-line, it becomes possible to study phenomena that were once essentially invisible: how our social networks are organized, how groups of people come together and attract new members, and how information spreads through society. With computational and mathematical ideas, we can begin to map the rich social landscape that emerges, filled with "hot spots" of collective attention, and behaviors that cascade through our networks of social connections.