Students need to practice material to gain mastery and spacing out that practice has shown to be effective. Another important concept is interleaving. Interleaving refers to re-introducing material in a different contexts, mixing together concepts such that the student must re-access the material in a different circumstance. The bulk of the original research on both retrieval practice and interleaving have been completed in controlled laboratory settings, but less has been done in a real classroom settings. And, for most of the studies that have been done to date, very few have combined two different findings, both with empirical evidence to support their efficacy, into one study. Drs. Compton and Fowler each taught one section of an introductory biology course and incorporated a study design where the two sections were taught in a similar manner, with the exception that one section was required to perform interleaving/retrieval practice throughout the semester, and one section was not (traditional). Homework, quizzes and exam questions were pulled from a prepared test bank shared between the instructors, with each question labeled with an identifier to facilitate tracking throughout the semester. The final exam was identical between the sections. The response variable measured were the final exam scores, compared between the experimental retrieval practice section and the traditional control section.
Results/Conclusions
Throughout the fall semester (2018) Compton’s introductory biology section performed interleaving and retrieval practice while Fowler’s section did not. To test against treatment effect of professor, Fowler’s section (Fall 2019) performed interleaving and retrieval practice while Compton’s section did not. Upon completion of the fall semesters (2018 and 2019) an identical final exam was administered between the sections. Using R, we ran an ANOVA with an interaction term between treatment and professor. There was no significant difference between treatment and professor. The calculated traditional section mean (n=123) was 73.4, while the calculated treatment section mean (n=122) was 74.3. A t-test showed no significant difference between the means of the two groups and while the results were not significant, it is in the expected direction. Interleaving and space retrieval has been shown to be more effective than traditional practices for developing the skills of problem solving and also leads to better long-term retention and improved ability to transfer learned knowledge. Interleaving improves the brain’s ability to differentiate, or discriminate, between concepts and strengthens memory associations.