For learners: how to remember what you learn

When we cram, our short term memory is activated, and we have access to information in the moment. We can perform immediately after cramming and as a result, we tend to believe that we will be able to perform later on. Our feeling of fluency – the feeling that we know and understand something - prevails. But that feeling of fluency may be an illusion: studies show that cramming leads only to short term learning but that spacing out study sessions, a learning technique called spaced repetition, will lead to better performance and long term retention of information.

Similarly, when we study one topic intensely (a particular set of math problems for instance) and then move on to another set, we tend to believe that because we understand how to solve each separate set of problems, we will be able to do so later on. But by focusing on one set of problems at a time, we rob ourselves of a crucial element of learning – the ability to practice comparing problems and approaches. Faced with an exam of a mixed set of problems, we can’t tell which approach to take with which problem; we studied each case separately.

To remember what we learned, we need to practice interleaving or mixing up the kinds of problems we study in any given session. Studies have shown that interleaving is a powerful learning technique. In one such study, art students were asked to learn the styles of different artists. In one condition, students were presented with paintings by one artist at a time; in another condition, students were presented with the works of different artists at the same time. The study showed that students who were shown a mixed set of paintings outperformed students who were shown the paintings of one artist at a time. Mixing up the practice of skills prompts us to notice similarities and differences, and allows us to generalize (and work from examples to principles), a difficult but important skill.

How can you put these ideas into practice?

By making small but powerful changes to your study habits:

Burstiness works. Space out your study sessions so that you don’t have to cram. If you have a week to study, space out your study throughout that week. Cramming may feel like learning but it doesn’t work for long term retention.

Let yourself forget. There is a lot of power in forgetting. When we learn a concept and then leave it for a while and let ourselves forget it, once we restudy that concept, our memory grows stronger; far stronger than if we had studied in one burst.

Invest in planning, not more studying. Spacing out your study sessions does not mean that you have to spend more time studying. You can plan to study at set intervals while still investing the same amount of time in the work. It’s not about more time, it’s about how you use that time.

Mix it up. To understand the underlying principle of anything you need to practice comparing and contrasting it with something else. While this may feel less satisfying than studying one thing at a time (you may not experience that same feeling of fluency) mixing up what you study will heighten your alertness – and you will have greater access to what you studied when you need it.

Works Cited

Kornell, N., Castel, A. D., Eich, T. S., & Bjork, R. A. (2010). Spacing as the friend of both memory and induction in young and older adults. Psychology and aging, 25(2), 498.

Lang, J. M. (2016). Small teaching: Everyday lessons from the science of learning. John Wiley & Sons.

Schwartz, D. L., Tsang, J. M., & Blair, K. P. (2016). The ABCs of how we learn: 26 scientifically proven approaches, how they work, and when to use them. WW Norton & Company.

Yan, V. X., Bjork, E. L., & Bjork, R. A. (2016). On the difficulty of mending metacognitive illusions: A priori theories, fluency effects, and misattributions of the interleaving benefit. Journal of Experimental Psychology: General, 145(7), 918.