"If you put a group of ordinary people together and aggregate their individual decisions, they can make better decisions than a few elite experts. There are four conditions for the wisdom of the crowd to surface: the first condition is diversity.” 


—Yuqing Ren

Online groups whose members span a diverse mix of experience levels and interests are more productive in accomplishing collaborative tasks and more satisfied with their work than groups with similar members.

In an effort to better understand how the types of members who make up online groups impact group outcomes, Assistant Professor Yuqing Ren and her colleagues examined data from 648 WikiProjects— groups of unpaid volunteers who band together to improve Wikipedia. They measured how interest and tenure diversity affects productivity and member retention over time.

Group diversity refers to the degree to which a group of people are similar or different in their backgrounds and attributes. Ren and her co-authors examined diversity along two dimensions: the types of topics that users most commonly contribute to (interest), and the length of time users have been Wikipedia editors (tenure).

They discovered that projects with a moderate level of tenure diversity accomplish more work and retain members better than projects with either very low or higher levels of diversity.

"Projects perform the highest when you have a moderate level of tenure diversity, meaning the group has a balanced set of newcomers, old timers, and people in the middle," says Ren, of her findings. "In general, a higher level of interest diversity is good for the project: it helps people get more done and it helps get the members to stick around." 

Ren believes diversity enriches a project because experienced users and newer users tend to embrace different but equally important roles in accomplishing a goal.

"If you have a nice mixture of people with various levels of experiences, you have both the skills that are required to do the high level structuring, and effort of the newcomers to fill in the little details,” she says.

They also found that over time, project diversity evolved toward the optimal performing zone as a result of members voluntarily joining and leaving the group. In light of this evidence, Ren encourages organizations to rethink how they manage their project teams, and consider new practices to empower employees and unleash the power of self-organizing.

Watch Ren further desribe her findings:


“The Impact and Evolution of Group Diversity in Online Open Collaboration”
Ren, Yuqing; Chen, Jilin; Riedl, John, Management Science (forthcoming)