Why do some pupils seem to get stuck on a topic while their classmates have no problem at all? Research by Jan Meyer and Ray Land into undergraduates studying economics might help us to understand the problem.

Meyer and Land identified what they termed “threshold concepts” - ideas that are so central to understanding a particular topic that pupils can’t progress further until they have fully understood them. In their work Overcoming barriers to student understanding (2006), they suggest that a threshold concept has the following characteristics:

• It is transformative; it changes the way you see the world.
• It is troublesome; it might seem counterintuitive or alien.
• It is irreversible; its transformative nature means that once it is learnt it is unlikely to be forgotten.
• It is integrated; it reveals connections between the different parts of the disciple.
• It is bounded; the concept has defined parameters to which it applies.
• It is discursive; it leads to the development of new language.

One threshold concept I come up against all the time in geography is the idea of the world as a three-dimensional sphere rather than the two-dimensional map projection that students are used to seeing. Failing to grasp this concept prevents them from understanding the relative size and position of landmasses, the use of longitude and latitude, transport and trade routes, world history and issues over power and border. But once students understand the world as a globe, their view of our planet is transformed.

Planning around threshold concepts

We can also see how threshold concepts might work when teaching a subject like coasts. To teach this topic, students have to be secure in their knowledge of wave processes. If they don’t understand how waves shape the coast, they can’t access later work on the formation of coastal landforms or the management of coastal areas. However, once they have grasped this threshold idea, they could, in theory, work out for themselves how landforms are created and shaped. And it certainly makes it much more straightforward for you to teach about this process.

Threshold concepts carry a number of implications for our planning:

1. Firstly, we need to identify the threshold concepts in our subject by looking for those key ideas that the rest of a topic is based on.
2. When planning a spiral curriculum (in which students encounter the same topics at different stages), we want to make sure that we address threshold concepts early on, and plan to revisit them often.
3. We should test students’ understanding of these concepts to make sure they are ready to move on. If they aren’t secure in their understanding of the threshold concepts, it will be a waste of time to move on to the next topic.
4. It is important that we then plan how to close these knowledge gaps for students who haven’t grasped the key concepts.

By paying attention to these key concepts and ensuring that students truly grasp them, we can be confident that they will be able to cross the threshold to a much deeper understanding.

Mark Enser is head of geography at Heathfield Community College and blogs at teachreal.wordpress.com