There’s been a noticeable increase in the amount of pedagogical literature that references what’s been documented about learning in cognitive psychology. It seems to be part of the ongoing interest in making instructional practices more evidence-based. But there’s an issue that makes the application of these research findings challenging. Most of the research in cognitive psychology has been done in labs or simulated classrooms. It hasn’t been done in actual classroom and for reasons that make sense.
First, classes enroll students who need to take the course. That cohort may or may not be representative of the average classroom—there may be more males than females, more students with high GPAs, more students from a particular major, and any number of other differences with the potential to influence the outcome depending on what’s being studied. Then there’s the very dynamic nature of the classroom. There’s all sorts of variables that are difficult, if not impossible to control. The content isn’t the same, even if the same teacher presents it. The interaction between and among the students can influence what’s learned and how it’s learned. Classroom policies create environments that are experienced differently by students. Compared to what occurs in labs, the learning that happens in classrooms is messy.
But unless a technique is studied in the dynamic milieu of the classroom, conclusions about its effectiveness must be offered tentatively. It worked in the lab, but does that mean it works in the classroom?
Fortunately, mostly in the field of psychology, there’s an increased effort to explore the “ecological validity” (read, classroom application) of techniques that have been shown to have positive effects on learning outcomes in laboratory and simulated classroom studies. Rachael Blasiman conducted just such of study of two strategies—distributed practice and interleaving. Distributed practice is study spaced across time intervals. It’s the antithesis of cramming. Interleaving is a study technique in which material from different class sessions or readings is studied during a single class session.
Both of these techniques have been studied thoroughly by cognitive psychologists but Blasiman references work that cites three problems with the research on distributed practice.
- The length of time between the study sessions needs to be lengthened. In research it’s often just hours, but classroom exams are spaced across weeks.
- The study sessions need to involve the amount and diversity of content typical in most courses.
- The content students are studying needs to be more complex. In lab studies, the content is often vocabulary words or simple problems.
“Few studies have used classroom stimuli and even fewer have used the more abstract concepts often covered in college-level courses.” (p. 47) Interleaving can be critiqued similarly. The few studies done in classrooms were done with students in grade school and the content used in the studies was much less abstract than the content in college courses.
Blasiman’s study explored a use of distributed practice and interleaving in introductory psychology courses. Students in the experimental sections reviewed concepts covered in the previous class session and randomly selected concepts from other sessions for 5-10 minutes at the beginning of every class. Blasiman hypothesized that students who reviewed this way would out-perform those in class sections that did not review. She also proposed that the more times the concept was reviewed, the better students would perform on exam questions that tested knowledge of it. Both of those hypotheses were confirmed. “Students in the experimental condition performed 8% better on the final exam than students in the control condition.” (p. 48) There was also some evidence “that the number of times a concept is reviewed is related to [better] exam performance.” (p. 48)
Research in this actual classroom setting raised questions that merit further exploration. For example, was it the review that caused the improved performance or did identifying a concept for review cause students to believe it was important (and therefore likely to be on the exam), which caused them to study it more?
Although this research co-mingled distributed practice and interleaving, thereby making it impossible to separate the unique contribution of each to the students’ better performance, it does show how useful it is to take techniques that have been shown to work in labs and explore how they function in an actual classroom. This study marks a starting point. “Future work in this area should examine the effectiveness of this technique in other disciplines, in online classes and in classes of various sizes.” (p. 49) One study does not “prove” that distributed practice and interleaving garner the same results when they are used in classes, but it begins to make the case.
Reference: Blasiman, R. N., (2017). Distributed concept reviews improve exam performance. Teaching of Psychology, 44 (1), 46-50.
