Time Critical Social Mobilization: The DARPA Network Challenge Winning Strategy

It is now commonplace to see the Web as a platform that can harness the collective abilities of large numbers of people to accomplish tasks with unprecedented speed, accuracy and scale [10]. To push this idea to its limit, DARPA launched its Network Challenge, which aimed to “explore the roles the Internet and social networking play in the timely communication, wide-area team-building, and urgent mobilization required to solve broad-scope, time-critical problems” [5]. The challenge required teams to provide coordinates of ten red weather balloons placed at different locations in the continental United States. This large-scale mobilization required the ability to spread information about the tasks widely and quickly, and to incentivize individuals to act. We report on the winning team’s strategy, which utilized a novel recursive incentive mechanism to find all balloons in under nine hours. We analyze the theoretical properties of the mechanism, and present data about its performance in the challenge.1 1 Time-Critical Social Mobilization Crowdsourcing is to harness the collective abilities of large numbers of people to accomplish tasks with unprecedented speed, accuracy and scale [11, 23, 4]. A particularly challenging class of crowdsourcing problems require not only the recruitment of a very large number of participants, but also extremely fast execution. Examples include search-and-rescue operations in the aftermath of natural disasters, hunting down wanted outlaws on the run, reacting to health threats that need instant attention, and rallying supporters to vote in a political campaign. In time-critical social mobilization problems, it is often not practical, or even impossible, to create sufficient mobilization through mass media, due to the extremely high cost of reaching everybody, or due to severe infrastructure damage[14]. A full version of this paper can by found at http://arxiv.org/abs/1008.3172