Introducing desirable difficulty in STEM barrier courses with spaced retrieval practice

This Full-Length Research Paper investigates the difficulty imposed by spaced retrieval practice in nine introductory Science, Technology, Engineering, and Mathematics (STEM) courses. By improving student performance in these courses, evidence-based pedagogical practices have the potential to increase graduation and success in STEM fields. Spaced retrieval practice is a technique in which questions on the same topic are asked repeatedly over time with intermittent delays. Spacing may initially make retrieval more difficult because it requires learners to recall information from long-term as opposed to short-term memory. However, this difficulty may ultimately be “desirable” because spacing often produces memory benefits in the long-term. The current paper examines the difficulty imposed by spaced retrieval in the nine STEM courses, using data collected from a 3-year project funded by the National Science Foundation. Results indicated that the magnitude of the difficulty imposed by spacing varied widely across the diverse STEM barrier courses. We anticipate that we will find similarly wide variability in the effectiveness of spaced retrieval practice in students' final learning outcomes, which will be investigated in future work.