What People Say and What Scientific Research Says about Knowledge Retention?

Dulas, M. R., Schwarb, H., Cannavale, C. N. & Cohen, N. J., Jan 2021, Should context hold a special place in hippocampal memory? Chapter One – Psychology of Learning and Motivation, Federmeier, K. D. & Sahakyan, L. (eds.). Advances in Research and Theory, Academic Press Inc., p. 1-35 (vol. 75).

“Intuitively, it might seem impossible to explain the testing effect with a neural network model, because one might expect that training with an accurate input pattern (i.e., restudy) should be as or more effective than training with an incomplete pattern (i.e., retrieval practice). However, according to the EDL [Error-Driven Learning] principle, learning is driven by the gap between expectations and targets. Because learning in the neocortex uses a slow learning rate and overlapping representations, memories acquired in the neocortex are usually less precise than those learned in the hippocampus. Thus, during retrieval practice, the output generated by the hippocampus is more accurate than the one generated by the neocortex. The difference between the two outputs creates an error signal which trains the neocortex. On the contrary, during restudy, the correct pattern is presented to both the hippocampus and neocortex, so only a small error signal can be generated, limiting the effectiveness of neocortex training. In other words, testing enables the hippocampus to more effectively drive learning in the neocortex.”

Roediger, H. L., III, & Karpicke, J. D. (2006). Test-enhanced learning taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.

“Testing is a powerful means of improving learning, not just assessing it. Taking a memory test not only assesses what one knows, but also enhances later retention, a phenomenon known as the testing effect. We studied this effect with educationally relevant materials and investigated whether testing facilitates learning only because tests offer an opportunity to restudy material. In two experiments, students studied prose passages and took one or three immediate free-recall tests, without feedback, or restudied the material the same number of times as the students who received tests. Students then took a final retention test 5 min, 2 days, or 1 week later. When the final test was given after 5 min, repeated studying improved recall relative to repeated testing. However, on the delayed tests, prior testing produced substantially greater retention than studying, even though repeated studying increased students’ confidence in their ability to remember the material.”

Carpenter, S. K., Pashler, H., Wixted, J. T., & Vul, E. (2008). The effects of tests on learning and forgetting. Memory and Cognition, 36(2), 438–448.

“In the present study, it is clear that testing produced better overall recall than did restudying. One reason for this benefit could be that the act of recall per se is more beneficial than studying the material again. Many past studies have shown that tests without feedback are significantly more beneficial than restudy opportunities, at least when the information is recalled correctly on the intervening test (see, e.g., Carpenter & DeLosh, 2005, 2006; Kuo & Hirshman, 1996, 1997; Roediger & Karpicke, 2006a, 2006b). In the case of tests with feedback, another reason that tests may be beneficial is that they reveal which items have been sufficiently learned and which ones require further study. For example, after trying to recall something and failing, subjects may, in subsequent study opportunities (e.g., when correct answer feedback becomes available), find new and better ways of encoding the information (see, e.g., Izawa, 1992; LaPorte & Voss, 1975).
These results also help to inform researchers and educators about the practical benefits of testing over time. Information that has been tested will be remembered better over time than information that has been restudied. This test-induced benefit is apparently stronger when repeated tests over the same information are provided. These results suggest that tests should be utilized often in educational contexts to maximize retention of information over long time periods.”

Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students’ learning with effective learning techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4–58.

“To offer recommendations about the relative utility of these [below] techniques, we evaluated whether their benefits generalize across four categories of variables: learning conditions, student characteristics, materials, and criterion tasks.
Five techniques received a low utility assessment: summarization, highlighting, the keyword mnemonic, imagery use for text learning, and rereading. These techniques were rated as low utility for numerous reasons. Summarization and imagery use for text learning have been shown to help some students on some criterion tasks, yet the conditions under which these techniques produce benefits are limited, and much research is still needed to fully explore their overall effectiveness. The keyword mnemonic is difficult to implement in some contexts, and it appears to benefit students for a limited number of materials and for short retention intervals. Most students report rereading and highlighting, yet these techniques do not consistently boost students’ performance, so other techniques should be used in their place (e.g., practice testing instead of rereading).”