Constructivism dealt a blow

One of my tasks, when training to be a teacher, was to use a prepared set of questions to interview a group of 16-year-olds on their ideas about space. I remember that one question was about why satellites went around the Earth and all the students suggested that satellites have engines that are continually running in order to push them around. This is reasonable. These students probably hadn’t given the issue much thought until I asked them about it and many everyday objects work in this way; a car travelling around a circular track is pushed around the track by the driving force of its engine. It is not correct for satellites, however. There are no frictional forces to overcome in space and so the satellite is actually in free-fall; only one force acts on it, pulling it to the centre of the Earth. This is a weird idea to grasp and so I, and many other physics teachers, have devoted quite a lot of time to honing our explanations.

The purpose of the university exercise was to make it clear to me that students are not blank slates. Instead, they already have conceptions about why a lot of things occur and we need to bear these in mind. This is a key tenet of constructivism. I find it extremely useful to know about these misconceptions because I address them directly through explicit teaching. However, this is not the approach that we were encouraged to consider. Instead, drawing on Piaget, the implication was that we should get students to articulate these misconceptions and make predictions based upon them before having their attention drawn to conflicting evidence. For instance, I might point out that satellites couldn’t store anywhere near enough fuel to constantly fire their engines. For other misconceptions, I could perhaps set up a demonstration or experiment to refute the misconception.

I have two main problems with the idea of inducing such ‘cognitive conflict’. Firstly, the process is ego-involving. Making a student articulate an idea that he is not particularly committed to will deepen his commitment. He won’t want to be seen to be wrong. Anyone who has followed education debates on social media will know how irrational people can become when their ideas are criticised. They can start launching ad hominem attacks, objecting to tone or simply dismissing the evidence. It does not seem like something a teacher would deliberately invoke.

Secondly, it is manipulative. I would much prefer to present my ideas to students, tailored by my understanding of the key misconceptions, and let them decide what they wish to believe. I am happy to argue my case. Trying to trick them into it seems like amateur psychology. Even if a student decides that ‘this is what physicists believe and this is therefore what I have to say in physics class but I don’t buy it deep down’ then I think it is her right to do so. I am an incrementalist; I don’t think one big conflict will sort out conceptual change but the scales will gradually tip as the evidence stacks-up. In fact, I think this has happened with a number of education bloggers as they have changed their views on kooky educational theories.

On the other hand, cognitive conflict seems to be a key component of ‘cognitive acceleration’; a strategy that has achieved seemingly extraordinary success in science education, albeit without being widely replicated (although there is a large RCT running at present). The trouble with cognitive acceleration is that cognitive conflict is one of a battery of measures and so we cannot separate-out its effect.

Therefore, it was with interest that I read a new paper on the topic. The researchers designed a stripped back experiment in order to investigate the effect of cognitive conflict alone. It is a little artificial but this is deliberate in order to isolate the effect. As the authors note, no strong evidence has emerged in favour of cognitive conflict from more standard learning situations.

Participants were trained in one way of categorising bacteria before the method of categorisation changed. This enabled the experimenters to ensure that all participants had equivalent prior conceptions. Half the participants were then given both confirming feedback and disconfirming feedback on the new category. The other half were just given confirming feedback. The disconfirming feedback therefore represented the cognitive conflict.

Overall, the researchers found no positive effect of cognitive conflict. If anything, it marginally slowed-down learning. This was perhaps due to the working memory resources required to process the conflict.

Update: Perhaps inevitably, some of the commenters below have questioned whether cognitive conflict is actually a tenet of constructivism. It is probably worth reading my FAQ on constructivism. In this FAQ, I link from an article by ASCD which contains the following quote:

“…constructivist teachers structure lessons to challenge students’ suppositions. All students, whether they are 6 or 16 or 60, come to the classroom with life experiences that shape their views about how their worlds work. When educators permit students to construct knowledge that challenges their current suppositions, learning occurs. Only through asking students what they think they know and why they think they know it are we and they able to confront their suppositions.”