Why does learning through peer instruction work?

As you might have noticed by now, I’m a big fan of concept questions combined with “talk to your neighbor” peer instruction. And studies show that talking to your neighbor is often more successful in teaching you new things than listening to the lecturer is.

In their paper “Why peer discussion improves student performance on in-class concept questions“, Smith et al., Science (2009), try to separate two possible reasons for the success of peer instruction: Does learning gain through PI result from gains in understanding during discussion, or simply from peer influence of knowledgeable students on their neighbors?

In order to separate those effects, the authors first ask a multiple choice question, let the students vote, use peer instruction, and let students vote again. They then ask a very similar question, which students who didn’t vote correctly the first time for the first question likely wouldn’t be able to answer correctly, either. So if those students answer correctly now, that supports the idea that they gained understanding during discussion rather than being just influenced by the knowledgeable students in the previous case. And their data shows that the third vote consistently gives better results than the first vote, and, surprisingly, often even better results than the second vote after peer instruction.

The power of increasing understanding through conversations with the neighbor is also supported by 47% of students disagreeing with the statement “When I discuss clicker questions with my neighbors, having someone on the group who knows the correct answer is necessary in order to make the discussion productive”. Discussing concepts seems to be the key, not being convinced by someone more knowledgeable.