By Yana Weinstein

(cover image by MoneyforCoffee from Pixabay)

At this point, there have been hundreds of studies demonstrating that practicing retrieval of to-be-learned information can help us remember that information later. We’ve covered many such studies on this blog (see all our posts tagged with "retrieval practice"), and regular readers will be very familiar with this idea. This finding has also started to find its way to broader circles, with popular articles, videos, and classroom implementations of the technique proliferating.

However, less well known is the finding that practicing retrieval of some information can actually, in some cases, help you learn new information that you study after you’ve practiced retrieval on the old information. This can start getting complicated to think about abstractly, so let’s break down what this might look like.

Imagine you study a list of words. Then, I'm going to show you another list. And another. And another....all in all, I'm going to show you 5 lists of words in one study session, but let's pretend I'm only interested in how well you learn the last list. I'm also going to vary what happens between lists. You can either just take a break for 2 minutes, restudy the words in the list, or you can retrieve (type out from memory) the words that you just saw in the previous list. The "forward testing effect" is the finding that practicing retrieval between lists helps us learn that last list, relative to taking a break or restudying the previous list. The figure below summarizes this procedure, which was used in the original study on this effect (1) and multiple follow-up studies (2), (3).

This type of experiment with the lists of words is at what we would call the "basic laboratory level". That is, the materials are not very realistic (why would we want our students to learn random lists of words?), and the setting is a controlled lab environment. But, this finding has also been replicated in various applied laboratory settings. For example, my colleagues and I had students learn face-name pairs instead, which is a more realistic scenario (4); and others had students study brief video lectures with a break, restudy the information of the video, or practice retrieval in between (5). In each of these cases, practicing retrieval in between chunks of information helped students learn the last chunk.

As is the case with retrieval practice itself, we haven't yet settled the debate on exactly why this happens. In fact, a recent review of the literature identified 8 different theories (including one of mine)! If you'd like to delve into the proposed theories, I highly recommend this open access review (6).

One note of caution: in some cases, retrieval can actually hurt later learning of new information. In a previous blog post, Dr. Miko Wilford described how switching frequently between retrieval practice of face-name pairs and new learning of face-profession pairs was harmful to the new learning (7). We are currently writing up a set of studies that extends these results to more classroom-relevant materials, with students learning associations between flags, countries, and other geographical features.

References:

(1) Szpunar, K. K., McDermott, K. B., & Roediger III, H. L. (2008). Testing during study insulates against the buildup of proactive interference. Journal of Experimental Psychology: Learning, Memory, and Cognition, 34, 1392-1399.

(2) Pastötter, B., Schicker, S., Niedernhuber, J., & Bäuml, K. H. T. (2011). Retrieval during learning facilitates subsequent memory encoding. Journal of Experimental Psychology: Learning, Memory, and Cognition, 37, 287-297.

(3) Weinstein, Y., Gilmore, A. W., Szpunar, K. K., & McDermott, K. B. (2014). The role of test expectancy in the build-up of proactive interference in long-term memory. Journal of Experimental Psychology: Learning, Memory, and Cognition, 40, 1039-1048.

(4) Weinstein, Y., McDermott, K. B., & Szpunar, K. K. (2011). Testing protects against proactive interference in face–name learning. Psychonomic Bulletin & Review, 18, 518-523.

(5) Szpunar, K. K., Khan, N. Y., & Schacter, D. L. (2013). Interpolated memory tests reduce mind wandering and improve learning of online lectures. Proceedings of the National Academy of Sciences, 110, 6313-6317.

(6) Yang, C., Potts, R., & Shanks, D. R. (2018). Enhancing learning and retrieval of new information: a review of the forward testing effect. npj Science of Learning, 3, 8.

(7) Davis, S. D., Chan, J. C. K., & Wilford, M. M. (2017). The dark side of interpolated testing: Frequent switching between retrieval and encoding impairs new learning. Journal of Applied Research in Memory and Cognition, 6, 434-441.