By Althea Need Kaminske

A few weeks ago I wrote about the effects of prior knowledge on new learning. I reviewed research which found that students who had stronger prior knowledge of a topic were more likely to remember more new information on that topic (1). This suggested a “rich-get-richer” effect, where it is easier to learn new information if you already know something about it. 

One of the challenges to studying the effects of prior knowledge on learning is that it is difficult to control in an experiment. In the Witherby and Carpenter (2021) paper that I described in my previous post, they simply asked participants to take a quiz that assessed their prior knowledge (1). So while they identified who had strong prior knowledge they did not manipulate prior knowledge. One of the limitations of this is that we don’t really know how they came by this prior knowledge. It’s possible that the cooking and football experts had some unknown characteristic that contributed to both their cooking/football knowledge and their ability to learn information within that domain. This highlights one of the trade-offs that happen when we conduct research on complex topics. Prior knowledge takes a long time to develop, and our development of that knowledge is based on many factors. This makes it difficult to manipulate! 

I was therefore really interested to see a recent study that attempted to do just that - manipulate prior knowledge in order to examine its effects on learning. First I’ll go over the design and results of this study, then I’ll compare how they defined and measured prior knowledge in this study compared to the other one.

The Experimental Design and Procedure

Buchin and Mulligan (2022) wanted to better understand how retrieval practice is affected by prior knowledge (2). Participants were trained over the course of three days on historical geology (geologic time, minerals, rocks, and isotopic dating) and sensation and perception (color perception, auditory perception, cutaneous senses, and chemical senses). They were randomly assigned to learn about three of the four topics either within the domains of historical geology or sensation and perception. In this training phase they read passages with graphics and multiple-choice knowledge checks. Each lesson took about 45 minutes and participants went through one lesson a day.

• Training Phase: Learn about three topics within a domain

After three days of learning about these topics, they were given four short passages on topics within their domain during a learning phase. Three of the topics were ones that they had received previous training on, and one was on a topic that they did not learn about in training. Thus, they had higher prior knowledge on some of the material, and lower prior knowledge on other material. Then, they either restudied these topics or they practiced retrieval with them.

• Learning Phase: Learn additional information on those three topics (High Prior Knowledge), plus a topic from within the domain that was not previously trained (Low Prior Knowledge).

Finally, two days later they took a final test on both historical geology and sensation and perception. The final test contained questions that were classified as Retention (questions that were identical to what appeared during the learning phase), Near Transfer (questions that were similar to what was studied during the learning phase), or Far Transfer (questions over information that was initially studied but never restudied or retrieved).

• Testing Phase: Test over all domain topics that includes Retention, Near Transfer, and Far Transfer questions.

The Results

Overall, participants who practiced retrieval remembered more on the final test than participants who restudied. And, higher prior knowledge of a topic led to better performance on the final test than lower prior knowledge. However, there was no interaction. When someone had higher prior knowledge of a topic, they benefited just as much from retrieval practice as when they had lower prior knowledge. Retrieval practice is equally beneficial, regardless of prior knowledge.

However, it is worth noting that the the effect was different depending on the type of question being asked in the final test. Retrieval practice was most beneficial for the Retention questions, somewhat beneficial for the Near Transfer questions, and not at all beneficial for the Far Transfer questions. Since these questions were about information that was never restudied or retrieved it’s not surprising that retrieval did not have an effect on this information.

Bottom Line

This is good news for educators! Retrieval practice works regardless of how much prior knowledge your students have. 

This was a really interesting study to read right after reading the Witherby and Carpenter (2021) study. Both looked at the effects of prior knowledge on learning, but they used different tasks to examine how that worked. In the Witherby and Carpenter paper they did not manipulate prior knowledge, and participants did not get to engage in retrieval practice with the new material. While there was less experimental control in how prior knowledge was obtained, this provides a more ecologically valid measure of prior knowledge. In other words, it measures prior knowledge as it happens out in the real world where people develop knowledge and expertise on topic areas over the course of months and years. In the Buchin and Mulligan paper, they manipulated prior knowledge and examined how that affected retrieval practice. While they had more control over how prior knowledge was obtained and could ask more specific questions about its effects, this type of prior knowledge is certainly different than the prior knowledge that students my have based on years of experience before coming into a classroom. Both papers tell us something valuable about how prior knowledge affects learning. Examining these two papers side-by-side highlights the importance of drawing on a body of literature to enhance our understanding of learning processes. It also highlights the complexity of teaching and learning!

References

1. Witherby, A. E., & Carpenter, S. K. (2021). The rich-get-richer effect: Prior Knowledge predicts new learning of domain-relevant information. Journal of Experimental Psychology: Learning, Memory, and Cognition, 48(4), 483-498. https://doi.org/10.1037/xlm0000996

2. Buchin, Z. L., & Mulligan, N. W. (2022, September 22). Retrieval-based learning and prior knowledge. Journal of Educational Psychology. Advance online publication. http://dx.doi.org/10.1037/edu0000773