An interesting research project at Northwestern University used the vast number of mobile users on campus to help academics retrieve photos and other pertinent data that they couldn't find simply by trolling data online. The problem researchers had to find an answer to was how to get users to go to places that they normally wouldn’t go to collect the data they needed.
Fabian Bustamante, associate professor of electrical engineering and computer science at the McCormick School of Engineering, used the Lincoln Memorial as an example. He noted that there are thousands of Flickr photos that can be used to compile 3-D virtual representations of various landmarks, but most people never take a picture of the back of the monument.
“Take the Lincoln Memorial, for example,” said Fabian Bustamante, associate professor of electrical engineering and computer science at the McCormick School of Engineering. “Flickr has thousands of photos of the front of the Lincoln Memorial. But who takes a picture of the back? Very few people.”
Realizing that they couldn't force users to do things they didn't want to or normally wouldn't do, researchers had to come up with a clever way to trick them into doing their bidding. Researchers finally settled on using what they call "soft control" on mobile users via a game.
“We can rely on good luck to get the data that we need," Bustamante said, "or we can ‘soft control’ users with gaming or social network incentives to drive them where we want them."
The research is detailed in the paper, "Crowd (Soft) Control: Moving beyond the Opportunistic." Written by Bustamante and his group, the paper details how they designed a way to soft control people’s movements by tapping into games and social networking applications. For example, a game player might get extra points if they visit a certain location in the real world, or an app might direct a player to a certain location in a virtual scavenger hunt.
Most of the testing was conducted using an Android game they created called Ghost Hunter. In it players chase ghosts around their neighborhoods and zap them through an augmented reality display on their phones. The player is actually taking a photo of the spot where the ghost is supposedly located. In Ghost Hunter the researchers manipulated where ghosts were placed, which in turn was used to drive players to locations that were important to them. The game was tested by Northwestern students, who were told only that they were testing a new game. They had no knowledge of which ghosts were placed randomly and which were placed for research purposes.
“We wanted to know if we could get the players to go out of their way to get points in the Ghost Hunter game,” Bustamante said. “Every time they zapped a ghost, they were taking a photograph of Northwestern’s campus. We wanted to see if we could get more varied photographs by ‘soft controlling’ the players’ movements.”
Researchers found that many players were willing to travel out of their way to play the game. For example, researchers collected photos of Northwestern’s Charles Deering Library from a number of unique angles and directions. Of course, this proved to deliver a broader range of data than anything they could get from random sampling found on Flickr.
“Playing the game seemed to be a good enough vehicle to get people to go to these places,” said John P. Rula, a McCormick graduate student and the lead author of the paper.
Researchers note that if this kind of technology were to be implemented on a larger scale, users would have to be notified that their data was being collected for research purposes.
“Obviously users need to know where their data is going,” he said, “and we take every measure to protect user privacy.”
The paper was presented in February at the Thirteenth Workshop on Mobile Computing Systems and Applications (HotMobile).