ATLANTA – The Georgia Tech team that chased the red balloons released in the U. .S. Defense Advanced Research Projects Agency (DARPA) Challenge came in second behind M.I.T., but its efforts yielded insights just the same, it says.

The DARPA Challenge attracted hundreds of teams to tackle the problem of how to locate the balloons, which were positioned Dec. 5 at locations ranging from San Francisco and Portland to Memphis and Miami.

A team from the Massachusetts Institute of Technology won the $40,000 prize for correctly locating all 10 balloons.  A team led by researchers at the Georgia Tech Research Institute (GTRI) found nine of the 10 balloons during the nine-hour competition.

Goal: assessing social networks

DARPA’s interest in the competition was in assessing how social networks could be used to address massive information-gathering tasks.  In addition to its research component, the challenge also marked the 40th anniversary of the ARPANET, the forerunner of today’s Internet.

GTRI researchers Erica Briscoe and Ethan Trewhitt established a Web site and began using Facebook and word-of-mouth communications to build a network that eventually included more than a thousand people pledged to help.

An early decision that they would donate the prize to the American Red Cross if they won turned out to be key in helping them attract volunteers and balloon spotters.

Early decision a key

“One thing that surprised us was that many balloon reporters specifically chose our team because we had decided to donate the winnings,” said Betty Whitaker, a GTRI principal research scientist who helped coordinate the team.

Another key was establishing the Web site “I Spy A Red Balloon,” which built a high ranking on Google thanks to references on established Web sites.  That allowed the team to attract people who may have seen a red balloon on Dec. 5 and wondered what was going on.

Not everyone could be trusted

“Though we focused on getting the word out to the public prior to launch day, our strong presence on that day made it possible for people who were unaware of the competition to find our team after running across a balloon,” explained Trewhitt, a GTRI research engineer.

But as with popular social networking services, not everybody could be trusted.

“Because teams were commonly infiltrated by members of competing teams, one of the toughest parts of this competition was not being able to trust any particular members of the group,” Trewhitt added.  “This led us to realize that trust in large groups is a tricky issue – and a topic for future research.”

They also used a variety of tools, some of which they built, to help track sightings.  Their Web site, for instance, used Google Maps to summarize reports.

Seeds for future research planted

Though the GTRI team didn’t win the top prize, its leaders believe the effort established credibility and planted seeds for future research projects.

“We would like to study issues of trust in large social networks, as well as how to extract and validate useful and correct information from un-moderated online media such as Twitter,” said Erica Briscoe, a GTRI research scientist.

“Twitter is often the fastest medium for notification of real-time events because it is unfiltered and raw.  It would be useful to research methods for determining the accuracy and authenticity of rumors in this type of environment.

The competition also showed how much could be done on a budget of just $200, which was what the “I Spy A Red Balloon” team spent in total.

DARPA plans to meet with all the teams to review their approaches and strategies used to build networks and collect information.

Online: www.gatech.edu