Wisdom of Crowds

At the 21C Learning Conference this past weekend, I heard James Surowiecki speak. He wrote a book called The Wisdom of Crowds. He shared many examples of circumstances in which a diverse crowd can give more accurate answers than any individual in the group. For example, a large crowd’s mean guess for the number of jelly beans in a large jar is often within 5% of the correct answer. Frequently the mean guess is better than any individual guess.

Surowiecki said that the key to a wise crowd is that it is diverse. When there are lots of differing guesses, the mean is more effective. But Surowiecki took this idea further and said that when a group needs to make decisions, a diverse group does better at this, too. On the other hand, a group of experts often all think the same as each other, and so do not always come up with creative solutions.

Surowiecki tried to make connections from his ideas and to issues facing the teachers at the conference. One useful idea is that a personal learning network (PLN) is more useful if it contains many different types of people. For me, this means I need to follow (on Twitter, for example) and talk to teachers from many different backgrounds. People with diverse skills will teach in different ways – and I should tap into this. Beginning teachers, for example, may not be experts but they have lots of new ideas to share.

But I was more struck by an idea that concerns teaching diverse groups of students. Surowiecki said that non-correlated mistakes don’t affect the wisdom of a group. In other words, as long as everyone is not making the same (type of) mistake, their work together will be greater than any individual contribution. I draw from this that I need to encourage a classroom atmosphere where everyone feels free to share ideas with none censored and all taken as valid. If students can share vastly differing ideas, then they are valuable even if they are wrong.

This made me think further about teaching groups of homogeneous students. A popular strategy in maths is to stream or set children by their ability. I can see that Suroweicki’s opinions can be used to argue against the wisdom of this. A more diverse group of students should be able to help each other learn better. Suroweicki didn’t go as far as saying this, but I believe this is a reason to teach in mixed ability groups.

Mixed ability teaching has been much on my mind lately – since arriving at West Island School I have had to teach more mixed ability classes than previously. Our year 7s are in mixed ability classes and our year 10s and 11s are in broadly mixed ability groups. I’ve (usually) enjoyed coming up with ways to differentiate work for these groups. But now I see that not only can students work together effectively in mixed groups, but perhaps they can even spur each other on to greater accomplishments because of their diversity. I can help this along by allowing (and requiring) discussion of ideas and methods among students of differing abilities.

Where do you stand on mixed ability teaching?