Let’s Get Practical: More Flashcards Are Better

Teachers certainly can benefit from background brain knowledge. It’s fascinating, for instance, to learn about the intricacies of neural network formation.

At the same time, we and our students often want practical classroom guidance. What exactly should we DO — and, in particular, what should we DO DIFFERENTLY?

For example: given the enthusiasm with which our students turn to flashcards, we should welcome any guidance on their best use.

Here’s a helpfully specific question: should our students use relatively small or relatively large stacks of cards?

Theory Meets Practice: Flashcard Strategies

Psychologists have a theory that should answer that question.

The “spacing effect” says that the same amount of practice spread out over time (“spaced“), rather than done all at once (“massed“), yields more learning.

If a student has — for example — only 5 flashcards in a pile, then she’ll encounter those words more frequently. On the other hand, if she has 20 flashcards in that  pile, then more time passes between each repetition.

5 flashcards = massing; 20 flashcards = spacing. Therefore, 20 flashcards ought to be better.

Nate Kornell, a practical researcher who writes with welcome clarity, tried just this experiment.

Students learned some word pairs with 4 piles of 5 flashcards each. They learned other word pairs with 1 pile of 20 flashcards.

Which flashcard strategy led to better recall the following day?

As the theory predicted, the larger pile of flashcards lead to better memory. In one trial, massed practice resulted in score of 38%. Spaced practice led to a score of 65%.

Crucially: students had the same amount of time to study the same number of words. Simply organizing those words one way (the big pile) rather than the other way (little pile) resulted in more learning.

A Paradox, and a Resolution

In Kornell’s study, larger stacks of flashcards yielded more learning for 90% of the students. And yet, even after they themselves had tried both approaches, 72% preferred the (ineffective) small stacks.

What gives? Why do they prefer ineffective flashcard strategies?

Kornell suspect that students prefer the study approach where they feel they’re making faster progress. Sadly, as happens quite often, the strategy that feels good in fact creates less learning.

Another example of this phenomenon: students typically prefer to reread passages rather than quiz themselves. Rereading doesn’t help them learn much, but it does make them feel more confident. (“I recognize that part! I must have learned it…”)

Flashcard Strategies: The Perfect Number

Given Kornell’s research, it’s tempting to think that students should always sort their flashcards into stacks of 20.

Instead of focusing on number, we should instead focus on relative challenge. The flashcard pile should be big enough so that

a) students feel stretched by the information they’re practicing, but

b) they don’t feel discouraged or overwhelmed.

That number will probably be higher than they would naturally choose. But it won’t be huge.

We might prefer to have more precise guidance than this. However, no one rule will apply equally well to all students.

The correct number of cards in a pile will be different in 2nd grade, 8th grade, and college. It will be different in subjects when students struggle and in subjects where they thrive. It will be different for flashcards that contain a lot of information and those with just a word or two.

Combining our teacherly experience with Kornell’s researcherly insight will lead to the best result we can hope for: flashcard strategies that promote optimum learning conditions.