New research from Knowledge@Wharton explores some interesting questions, Is Your Team Too Big? Too Small? What's the Right Number?
Acknowledging that the right answer will vary depending on the task, the authors indicate that teams of 5 to 13 members are most common. Further, because of the Ringlemann effect, or social loafing, the authors argue that individual effort often decreases as team size increases. Thus, while a team with 9 members will likely have greater total effort than a team with 5 members, the smaller team is likely to experience greater per person contributions. Wharton management professor Katherine J. Klein put it this way,
My intuition is that by the time you are over eight or nine people, it is cumbersome and you will have a team that breaks down into sub-teams. Depending on the group's task, that could be a good thing or that could not be right. There is a sense that as a team gets larger, there is a tendency for social loafing, where someone gets to slide, to hide.
In my experience, the most effective teams have 4 to 6 team members. With groups of that size, it is fairly easy to hold meetings with 100% attendance, which is often difficult with larger teams. More importantly, smaller teams can more readily achieve common understandings about goals, processes, and norms. Team members are able to monitor the progress of each other to identify who needs support to achieve mutually agreed upon objectives.
I have found a couple of ways for larger teams to take advantage of some of the inherent advantages of smaller teams. As suggested in the Wharton article, teams can be broken up into sub-groups. This can work most effectively when project tasks break along natural lines, so that a sub-group can be responsible for a group of related tasks.
Other strategies are to have a smaller steering group or core group.
Steering groups are often made responsible for decision-making and planning for the larger team. While this tends to inject hierarchy into teamwork, which may not be appropriate for some projects, steering groups can be effective when the larger team has members who are newer to the organization, in junior positions, or otherwise not expected to be decision makers.
Core groups formed within larger teams are most practical when several team members are also assigned to other tasks and not expected to contribute fully to the entire project. Core groups would be made up of those members expected to be most involved with the entirety of the project.
While size is not the only factor that affects teamwork, effectiveness, and productivity – size matters.