I’ve posted a lot here recently about retrieval practice: the practice of reviewing material by pulling it OUT of the student’s head rather than trying to put it back IN.
For example: if I ask my students to write down the 5 main points from yesterday’s class about the Buddha, that’s retrieval practice. They have to get info out of their heads.
If, instead, I remind them of the 5 main points from yesterday’s class, that’s not retrieval practice. After all, I’m putting information back in.
The short sales pitch for retrieval practice is: it works for all students in all subjects, all the time. (Ask Dr. Pooja Agarwal.)
Of course, all students in all subjects all the time is quite a grand claim. It’s rare for any teaching practice to work all the time, so we should be on the lookout for boundary conditions.
And, indeed, one has recently jumped out at me.
The story is interestingly complicated. I promise, however, that a close study of this complexity leads to specific and useful teaching advice. So: hang in there!
When Retrieval Practice Timing Might Be Bad
Imagine that, in yesterday’s class, we went over ten definitions for key economics terms. I want to begin today’s class with a quick review, so we go back over five of those terms.
My assumption is that, by reviewing five, I’m actually helping you to remember all ten.
Here’s the surprising research finding: by practicing some of the terms, I actually make it LESS LIKELY that you’ll remember the unpracticed terms.
In other words: recalling some of the words prompts you to forget the unpracticed words.
Psychologists call this bizarre result retrieval-induced forgetting. After all, the retrieval — that is, the practice — induced you to forget.
When Research Fields Contradict
So: the retrieval practice research says that retrieval is beneficial for memory.
And: the retrieval-induced forgetting research says that retrieval is detrimental for memory.
What happens when teachers do both? Does one cancel out the other? Can Superman defeat Iron Man?
Research done by Jason CK Chan helps answer this intriguing question.
The short answer is: in the short term, retrieval-induced forgetting is stronger. So: if I quiz you on five of those economics terms, and then give you the final test on those terms an hour later, you’re more likely to forget the five unpracticed words.
However, in the longer term, retrieval practice is stronger. So: the quiz on five terms will benefit you if you take that final test 24 hours later.
This result is especially likely if my quiz encourages you to think about how these five words connect conceptually to the other words.
Although these research findings can be difficult to follow, they do all lead to a specific suggestion.
Retrieval practice is an excellent study strategy for students more than 24 hours ahead of a test. However, within that 24 hour window, teachers and students should focus more on connecting ideas rather than recalling them.
To update Dr. Agarwal’s guidance: retrieval practice works for all students in all subjects, (almost) all the time.