Paper Review: The Critical Importance of Retrieval for Learning

Karpicke, J. D., & Roediger, H. L. (2008). The Critical Importance of Retrieval for Learning. Science, 319(5865), 966–968. doi:10.1126/science.1152408  

Summary: This paper reports the research which had following three goals:

1. Once information can be recalled from memory, what are the effects of repeated encoding (during study trials) or repeated retrieval (during test trials) on learning and long-term retention, assessed after a week delay?
2. Examine students’ assessments of their own learning.
3. Is speed of learning correlated with long-term retention, and if so, is the correlation positive (processes that promote fast learning also slow forgetting and promote good retention) or negative (quick learning may be superficial and produce rapid forgetting)?

In the experiment, the researchers had college students learn a list of foreign language vocabulary word pairs and manipulated whether pairs remained in the list (and were repeatedly practiced) or were dropped after the first time they were recalled. Students in one condition learned foreign language vocabulary words in the standard paradigm of repeated study-test trials. In three other conditions, once a student had correctly produced the vocabulary item, it was repeatedly studied but dropped from further testing, repeatedly tested but dropped from further study, or dropped from both study and test.

Following are the results reported in this paper:

• Repeated retrieval practice enhanced long-term retention, whereas repeated studying produced essentially no benefit.
• Students’ predictions of their performance were uncorrelated with actual performance.
• Forgetting rate for information is not necessarily determined by speed of learning but, instead, is greatly determined by the type of practice involved.

Assessment:
The research presented in this paper has produced results that contradict the conventional wisdom. The conventional wisdom is that if information can be recalled from memory, it has been learned and can be dropped from further practice, so students can focus their effort on other material. Research reported in this paper shows that this conventional wisdom is wrong. Even after items can be recalled from memory, eliminating those items from repeated retrieval practice greatly reduces long-term retention. Repeated retrieval induced through testing (and not repeated encoding during additional study) produces large positive effects on long-term retention. This is very important contribution that needs further validation for generalization.

Reflection:
Continuous testing is considered to be a best practice in software development. Looks like it is also a best practice in education! On more serious note, this paper strengthens the argument that technology can enhance quality of learning since repeated testing is easier with use of technology.