ANN ARBOR—New research shows that people in online groups contribute more when issued a challenge and when they believe their effort provides a unique benefit.

Results could be used to design online communities that encourage increased participation. Hundreds of thousands of online communities exist for people to share news and information on issues and interests they have in common.

Researchers from the University of Michigan and collaborators from Carnegie Mellon, University of Minnesota and University of Pittsburgh, studied the problem of under-contribution to the communities by examining factors that motivated people to contribute to an online movie rating service called MovieLens.org. The paper, “Using Social Psychology to Motivate Contributions to Online Communities,” appeared in the proceedings of the Association for Computing Machinery (ACM) Conference on Computer Supported Cooperative this month.

Like most online communities, a handful of MovieLens members do much of the work. The site had 80,000 registered users with about 7,000 active in the six months prior to the research.

Besides providing insight into ways to motivate behavior online, other findings from the study contradict conventional wisdom about social loafing, a term used to describe the tendency for people to exert less effort in a group task than in a comparable individual task, said Paul Resnick, professor in the U-M School of Information and a co-author of the study.

“We found that giving people specific goals and targets even though they had no reason to accept those, if you just gave them specific challenges they contributed more,” Resnick said. “We also found that if you emphasize how unique their contributions are, they were willing to contribute more. Even in something so mundane as the uniqueness of what kind of movies you rate, that was enough motivation for them to rate more.”

The ability to apply the social science findings to online communities has many implications for the communities in existence, Resnick said, many of which fail because of under-contribution. Exploiting this knowledge of human behavior is a staple in successful fund-raising—for example, requests for large and specific dollar amounts from donors, the paper said—but until now the behavior wasn’t tested and validated in online communities.

Scientists conducted two tests: one that motivated contribution using wording that stressed the uniqueness and benefit of rating movies; and one that motivated contribution with language that set specific and challenging goals for the number of movie reviews.   The researchers communicated with the Movielens.org test and control subjects with differently worded e-mail messages. Some members did not receive e-mail messages.

In the motivation and benefit test, 47.8 percent of participants who received an e-mail invitation to rate a movie logged in and rated movies, compared to only 3.2 percent of the control group that did not receive an e-mail reminder. The control group rated only 9.1 movies per member logging in, compared to 39.7 movies per member who received the e-mail and logged in. Participants who received a message stressing the uniqueness of their contribution rated 18 percent more movies than those who did not.

In the goal-setting test, movie reviewers who received a specific numerical goal rated more movies than individuals who were simply told to do their best.  

“This is the first study to document that this finding from goal setting theory applied to contributions to an online community and should encourage designers to be more specific about assigning goals or providing opportunities for individuals to declare contribution goals for themselves,” the study stated.

For information on Resnick, visit: http://ipumich.temppublish.com/public/experts/ExpDisplay.php?ExpID=633

To download the paper, visit: http://www.si.umich.edu/~presnick/papers/cscw04/

For information on the Community Lab project, see: http://www.communitylab.org/

baileylm@umich.edu