Distributed Practice - The Scientific Way to Improve Student Performance

Is this a familiar story at your school? Students stay up late into the night cramming weeks' of material into one study session before the final exam, only to forget the material as soon as the exam is over. From our experience as educators, we know that poor long-term retention of study material is linked to cramming (i.e. when studying is concentrated into a single session). A better approach to long-term retention is distributed practice (i.e. when studying is spread across multiple sessions over time).

What is distributed practice?

The advantages of long-term memory retention, by the distribution of multiple practice or study sessions, are among the most powerful effects in modern memory research. Distributed practice (also known as spaced repetition or spaced practice) is a learning strategy, where practice is divided into a number of short sessions over a longer period of time. People learn things in a list more effectively if they study it in smaller parts over many small sessions spread out over a long period of time, rather than study repeatedly in a short period of time (spacing effect). Massed practice, which consists of fewer and longer studying sessions is the opposite of spacing effect, is generally a less effective method of learning. We already saw this in our example of the final exam, when spreading the study sessions more frequently over a longer period of time will result in more effective learning than intense study the night before the exam.

The Methodology - Why is distributed practice so effective?

Distributed practice and distributed learning effects were first observed by the influential German psychologist Hermann Ebbinghaus, and in an earlier study by Alan Baddeley and Longman. They researched the effectiveness of distributed practice by teaching postmen how to type using a new system on a typewriter, and comparing massed and spaced learning. They found that although massed practice would seem a more effective learning method because the participants would be able to learn the material in fewer days, the postmen who were taught using shorter sessions stretched over multiple days learned the material better than those who had the longer training sessions. Those who learned how to type with shorter learning sessions, spaced over more days ended up with more accurate and quicker typing. Multiple psychological functions are responsible for the beneficial effects of distributed practice. Theories of encoding and consolidation of memory (procedural learning, priming effects, and expanding retrieval) support distributed practice as a successful study strategy for the real world. The spacing effect and its underlying mechanisms have important applications to learning across domains like sports, languages, advertising, and educational contexts (assessment formats of free-recall, multiple-choice, short answer, essay, performance). For instance in advertising, the spacing effect dictates that it is not an effective strategy to present the same commercial back-to-back (massed repetition).

The Challenge - What can we do to implement distributed practice?

A dilemma faced by teachers, and by designers of educational software, is the trade-off between teaching new material and reviewing what has already been taught. Complicating matters, review is useful only if it is neither too soon nor too late, and moreover, different students learn differently and need to review at different rates. The challenge we are faced with is to adopt more effective learning strategies like distributed practice. We can enable students to retain their learnings in the long-term through the choices we make when planning our classes. The best is to start with small changes. Two particularly effective ways to start are:

1. Distribute testing throughout the semester, begin or end each class session with a review exercise, and/or add a few pop quizzes
2. Consider using classroom technology both for fun and efficient practice that helps students revise the study materials in small chunks spaced
   across multiple sessions with repetition

References:

Shana K. Carpenter & Nicholas J. Cepeda & Doug Rohrer & Sean H. K. Kang & Harold Pashler. Using Spacing to Enhance Diverse Forms of Learning: Review of Recent Research and Implications for Instruction. Educ. Psychol. Rev (2012) 24:369-378 DOI 10.1007/s10648-012-9205-z [pdf]

Aaron S. Benjamin and Jonathan Tullis. What makes distributed practice effective? Cogn. Psychol. 2010 Nov; 61(3): 228-247 [Link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2930147/]

Timothy P. Novikoffa, Jon M. Kleinbergb,1, and Steven H. Strogatza. Education of a model student. Proceedings of the National Academy of Sciences of the United States of America vol. 109 no. 6,1868-1873, doi: 10.1073/ pnas.1109863109 [http://www.pnas.org/content/109/6/1868.abstract]