The Limitations of Retrieval Practice (Yes, You Read That Right)

Last week, I wrote that “upsides always have downsides.”

That is: anything that teachers do to foster learning (in this way) might also hamper learning (in that way).

We should always be looking for side effects.

So, let me take a dose of my own medicine.

Are there teaching suggestions that I champion that have both upsides and conspicuous downsides?

Case in Point: Retrieval Practice

This blog has long advocated for retrieval practice.

We have lots (and LOTS) of research showing that students learn more when they  study by “taking information out of their brains” than “putting information back into their brains.” (This phrasing comes from Agarwal and Bain.)

So:

Students shouldn’t study vocabulary lists; they should make flash cards.

They shouldn’t review notes; insted, they should quiz one another on their notes.

Don’t reread the book; try to outline its key concepts from memory.

In each of these cases (and hundred more), learners start by rummaging around in their memory banks to see if they can remember. All that extra mental work results in more learning.

SO MUCH UPSIDE.

But wait: are there any downsides?

Let the Buyer Beware: Retrieval-Induced Forgetting

Sure enough, some researchers have focused on “retrieval-induced forgetting.”

Yup. That means remembering can cause forgetting.

How on earth can that be? Here’s the story…

Step 1: Let’s say I learn the definitions of ten words.

Step 2: I use retrieval practice to study the definitions of five of them. So, I remembered five words.

Step 3: Good news! Retrieval practice means I’ll remember the five words that I practiced better.

Step 4: Bad news! Retrieval-induced forgetting means I’ll remember the five words I didn’t practice worse. Yes: worse than if I hadn’t practiced those other five words.

In brief: when I remember part of a topic, I’m likelier to FORGET the part I didn’t practice. (Although, of course, I’m likelier to REMEMBER the part I did practice.)

So, retrieving induces forgetting. Now that’s what I call a downside.

Potential solution?

How do our students get the good stuff (memories enhanced by retrieval practice) without the bad stuff (other memories inhibited by retrieval practice)?

Here’s an obvious solution: tell our students about retrieval-induced forgetting.

Heck, let’s go one step further: tell them about it, and encourage them to resist its effects.

One research group — led by Dr. Jodi Price — tried just this strategy.

The research design here gets quite complicated, but the headline is:

They ran the same “retrieval-induced forgetting” study that others had run, and this time added a brief description of the problem.

In some cases, they added encouragement on how to overcome this effect.

So, what happened when they warned students?

Nothing. Students kept right on forgetting the un-practiced information (although they kept right on remembering the practiced information).

In brief: warnings about retrieval-induced forgetting just didn’t help. (Heck: in some cases, they seemed to promote even more forgetting.)

Alternative Solutions?

Much of the time, we benefit our students by telling them about reserach in cognitive science.

I routinely tell my high-school students about retrieval practice. I show them exactly the same studies and graphs that I show teachers in my consulting work.

In this case, however, it seems that sharing the research doesn’t help. Telling students about retrieval-induced forgetting didn’t stop retrieval induced forgetting.

Conclusion: it’s up to teachers to manage this side effect.

How? We should require retrieval of all essential elements.

For example:

When I teach my students about comedy and tragey, the definitions of those terms include lots of moving pieces.

I know that ALL THE PIECES are equally important. So I need to ensure that my retrieval practice exercises include ALL THE PARTS of those definitions.

Students don’t need to remember everything I say. But if I want them to remember, I need to ensure retrieval practice happens.

Each of us will devise different strategies to accomplish this goal. But to get the upside (from retrieval practice) we should mitigate the downside (from retrieval-induced forgetting).

TL;DR

Retrieval practice is great, but it might cause students to forget the parts they don’t retrieve.

Alas, we can’t solve this problem simply by warning our students.

So, we should structure our review sessions so that students do in fact retrieve EVERYTHING we want them to remember.

If we create such comprehensive retrieval, students can get the upsides and without the downsides.

Price, J., Jones, L. W., & Mueller, M. L. (2015). The role of warnings in younger and older adults’ retrieval-induced forgetting. Aging, Neuropsychology, and Cognition, 22(1), 1-24.