39 countries) as participants in the
Challenge, interview data and team
estimates of network size indicate
that more than 350,000 people participated in some way. Based on the
922 balloon sighting submissions to
the DARPA Web site and team interview data, DARPA tracked 58 teams
that were able to correctly locate at
least two balloons. Following the
Challenge, DARPA conducted 53 interviews with team leaders who had
competed in the Challenge. These interviews supplemented the quantitative submission-log data collected on
the DARPA Web site with qualitative
data about participating team strategies, social and technical tools used,
network size, mobilization speed,
and important social dynamic factors.
This data enabled DARPA to reflect on
the experience of teams beyond the
three in the CSCW session.
The Challenge clearly demonstrated
the variety, efficiency, and effectiveness
of crowdsourcing solutions to a distributed, geo-located, time-urgent problem. The network mobilization time
was far faster than expected by DARPA
program managers, requiring days
instead of weeks. The MIT team constructed a motivated network exceeding 5,000 individuals from four initial
nodes in just a few days. Other teams
that built around existing networks
were able to mobilize them in a day. In
one case, a highly connected individual
successfully mobilized his contacts
through Twitter in less than an hour. As
impressive as their use of the network
to discover balloons, many teams also
used it to do precise, targeted dispatching to verify balloon sightings. Balloon
verification, from initial report to confirmation by a targeted dispatch, was
typically less than two hours.
While the power of social networks
and the manner in which they are
poised to transform our society have
been gaining attention, the Challenge
revealed several promising means
for using them to mobilize groups of
people for a specific purpose. It also
demonstrated the speed at which so-
cial networks could be used to solve
challenging, national geo-location
problems. This potential has pro-
found implications for a variety of
applications, from natural disaster
response to quickly locating missing
children. However, the Challenge also
demonstrated this wealth of data is
very noisy, reflecting the need for bet-
ter search methods and verification
We thank the Computer Supported
Cooperative Work 2010 conference
co-chairs Kori Inkpen and Carl Gut-
win for supporting its “Reflecting on
the DARPA Red Balloon Challenge”
session. The MIT team thanks Alex
(Sandy) Pentland, Riley Crane, Anmol
Madan, Wei Pan, and Galen Pickard
from the Human Dynamics Labora-
tory at the MIT Media Lab. The iSchool
team is grateful for the support and
advice provided by John Yen, Da-
vid Hall, Wade Shumaker, Anthony
Maslowski, Gregory Traylor, Gregory
O’Neill, Avner Ahmad, Madian Khab-
sa, Guruprasad Airy, and Leilei Zhu of
Penn State University; Maeve Reilly and
John Unsworth of the University of Illi-
nois; Martin Weiss of the University of
Pittsburgh; Jeffrey Stanton of Syracuse
University; and Gary Marchionini of
the University of North Carolina. We
also acknowledge Ethan Trewhitt and
Elizabeth Whitaker from GTRI for their
participation in the CSCW session.
We also thank Peter Lee and Norman
Whitaker from DARPA and the DARPA
Service Chiefs’ Program Fellows who
conceived and executed the Challenge:
Col. Phillip Reiman (USMC), CDR Rog-
er Plasse (USN), CDR Gus Gutierrez
(USN), MAJ Paul Panozzo (USA), Maj.
Jay Orson (USAF), Timothy McDonald
(NGA), Capt. Derek Filipe (USMC), and
CPT Deborah Chen (USA).
1. brabham, d.c. crowdsourcing as a model for problem
solving. Convergence: The International Journal of
Research into New Media Technologies 14, 1 (2008),
2. burke, J., estrin, d., hansen, M., Parker, a.,
ramanathan, n., reddy, s., and srivastava, M.b.
Participatory sensing. In Proceedings of the Workshop
on World-Sensor-Web at Sensys (boulder, co, oct. 31,
3. buyukkokten, o., cho, J., Garcia-Molina, h., Gravano,
l., and shivakumar, n. exploiting geographical
location information of web pages. In the Informal
Proceedings of the International Workshop on the
Web and Databases (Providence, rI, June 28, 1999),
4. defense advanced research Projects agency. DARPA
Network Challenge Project Report. darPa, arlington,
Va, Feb. 16, 2010; https://networkchallenge.darpa.mil/
5. dodds P.s., Muhamad, r., and watts, d. J. an
experimental study of search in global social
networks. Science 301, 5634 (aug. 8, 2003), 827–829.
6. Greenemeier, l. Inflated expectations: crowdsourcing
comes of age in the darPa network challenge.
Scientific American (dec. 21, 2009); http://www.
7. Mason, w.a. and watts, d. J. Financial incentives and
the ‘performance of crowds.’ In Proceedings of the
KDD Workshop on Human Computation (Paris, June
28–July 1). acM Press, new york, 2009, 77–85.
8. Mercado, s. a venerable source in a new era: sailing
the sea of osInt [open source Intelligence] in the
information age. Studies in Intelligence 48, 3 (2004),
9. Milgram, s. the small world Problem. Psychology
Today 1, 1 (May 1967), 60–67.
10. Padamanabban, V. and subramanian, l. determining
the geographic location of Internet hosts. ACM
SIGME TRICS Performance Evaluation Review 29, 1
(June 2001), 324–325.
11. tang, J.c. special session: reflecting on the darPa
red balloon challenge. at the 2010 acM conference
on computer supported cooperative work (savannah,
Ga, Feb. 9, 2010); http://www.cscw2010.org/program/
12. trewhitt, e. Preparing for the darPa network
challenge (Feb. 24, 2010); http://cacm.acm.org/blogs/
John C. Tang ( email@example.com) is a senior
researcher in Microsoft research, Mountain View, ca.
Manuel Cebrian ( firstname.lastname@example.org) is an assistant
research scientist in the department of computer science
& engineering, university of california at san diego,
la Jolla, ca, though at the Massachusetts Institute of
technology, cambridge, Ma, at the time of this work.
nicklaus A. Giacobe ( email@example.com) is a Ph.d.
candidate and research associate in the college of
Information sciences and technology at the Pennsylvania
state university, university Park, Pa.
hyun-Woo Kim ( firstname.lastname@example.org) is a Ph.d. candidate in
the college of Information sciences and technology at
the Pennsylvania state university, university Park, Pa.
Taemie Kim ( email@example.com) is a Ph.d. candidate
in the Media laboratory of the Massachusetts Institute of
technology, cambridge, Ma.
Douglas “Beaker” Wickert ( firstname.lastname@example.org)
is a Major in the u.s. air Force and a program fellow in the
transformational convergence technology office of the
defense advanced research Projects agency, arlington, Va.
© 2011 acM 0001-0782/11/04 $10.00