In 1987, professor Jack Treynor held up a jar filled with jelly beans to his finance class. All 56 students chimed in with their guesses on how many beans were in the jar. The group’s estimate averaged to 871, 2.5% off of the correct answer of 850 and closer than all but one of the participants’ guesses. The implications? That a group’s ability to perform a task is largely superior to an individual’s.
This experiment has been repeated a number of times with similar results; additionally, other case studies show the individual’s knowledge based is dwarfed by the crowd’s. On the gameshow, Who Wants to Be a Millionaire?, the option to “Phone a Friend” for help with your question produces a correct answer 65% of the time. Keep in mind, this friend is one of three preselected “experts” with 30 seconds to provide a response, and the ability to access the world wide web. One the other hand, the TV studio audience, a motley crew of television enthusiasts, provides the correct answer when polled 91% of the time.
In regards to pedagogy, these findings highlight the benefits of collaborative learning. Inevitably, you will have a few students who dislike groupwork, but perhaps starting off the year with Treynor’s jellybean experiment will encourage their buy-in.