I am sure that we are all familiar with massed practice, or as it’s called before exams, cramming. The night before the exam we spend hours reading over our notes, gaining familiarity and fluency with their contents and the next day we get by in the exam. It works….to a certain extent, anyway. However, although ‘massed practice brings rapid gains…it is followed by rapid forgetting’ (Roediger, McDaniel & Brown) and the content is not available to the same extent the next time we need it. Unfortunately, just like re-reading many students believe that massed practice is better than distributed practice. Hitting the same shot in golf over and over, doing the same drill continuously in a football training session or interminably playing the same tune on the guitar gives us a superficial feeling of mastery, but this only lasts a short time.
Practice is far more effective when it’s broke into separate periods of training that are spaced out. However, this requires more effort – learning feels slower and it isn’t perceptible. Spacing out your practice feels less productive for the very reason that some forgetting sets in and you then have to work harder to recall the concepts. It doesn’t feel like you are on top of it, but the added effort is making the learning stronger. When the neural suitcase is packed carefully and gradually, it holds its contents for far, far longer (Benedict Carey).
What is the evidence for the ‘spacing effect’?
An hour of study tonight, an hour on the weekend, another session a week from now: such so-called spacing improves later recall, without requiring students to put in more overall study effort or pay more attention, dozens of studies have found. Hermann Ebbinghaus first identified the spacing effect phenomenon in 1885. He found that if he studied a list of meaningless syllables over three days rather than one he could cut his study time in half. Daniel Willingham, in his article ‘Allocating Student Study Time: Massed versus Distributed Practice’, describes another study in 1967:
‘Geoffrey Keppel (1967) had college students learn pairs of nonsense syllables and adjectives (e.g., lum-happy). They were to learn the list so that when they saw the syllable, they could provide the matching adjective. All subjects studied the list eight times, but for half of the subjects, all eight trials occurred on the same day (massed practice) and the other subjects studied the list two times on each of four successive days (distributed practice). Keppel tested their memory of the list either 24 hours after the final study session, or a week later.The results are shown in the chart on the left. The upshot is that the massed practice group does fairly well if they are tested the next day, but they show a considerable drop-off if they are tested a week later. The distributed practice group, on the other hand, shows very little forgetting, even after the delay.’
Bloom and Shuell (1981) also noted that students who were taught 20 new French vocabulary words in a 3 x 10 minute distributed sessions, rather than one 30 minute session, scored better four days later. Rea and Modigliani (1985) found similar results when third grade students were taught spelling words and math facts. Most interestingly, Donovan and Radosevich gave the spacing effect an effect size of d=.42, indicating that ‘the average person getting distributed training remembers better than about 67 percent of the people getting massed training’ (Willingham).The spacing effect was even shown to have an impact 8 years later in a study by Bahrick and Phelps.
In a piece that she wrote for the New York Times in September 2011, Annie Murphy Paul, author of Brilliant: The New Science of Smart, says ‘spaced repetition produces impressive results. Eighth-grade history students who relied on a spaced approach to learning had nearly double the retention rate of students who studied the same material in a consolidated unit, reported researchers from the University of California-San Diego in 2007. The reason the method works so well goes back to the brain: when we first acquire memories, they are volatile, subject to change or likely to disappear. Exposing ourselves to information repeatedly over time fixes it more permanently in our minds, by strengthening the representation of the information that is embedded in our neural networks.”
How could the ‘spacing effect’ be used in the classroom?
To a certain extent spacing already happens due to the nature of the school timetable. It is likely that most teachers see a class 2-4 times a week meaning the information presented to them is spaced over those days in a week. Where teachers need to give more consideration to is how they will revisit that content in a few weeks, months and even a year. If it isn’t covered again the advantages of the ‘spacing effect’ are missed.
Daniel Willingham advises that teachers should develop homework assignments that include material from previous units. He also recommends that teachers ensure students have the chance to practice on the material that will be on a final test several times spread out over the study period. This can be achieved by having 3-4 full practice tests, or mock exams, scheduled into the timescale of the course.
The authors of Make it Stick also say that teachers should design quizzes and exercises that reach back to concepts and learning covered earlier in the term, so that retrieval practice continues and the learning is cumulative, helping students construct more complex mental models, strengthen conceptual learning, and develop deeper understanding of the relationships between ideas or systems. Repeating key points also highlights the importance of the content.
Annie Murphy Paul says ‘instead of concentrating the study of information in single blocks, as many homework assignments currently do—reading about, say, the Civil War one evening and Reconstruction the next — learners encounter the same material in briefer sessions spread over a longer period of time. With this approach, students are re-exposed to information about the Civil War and Reconstruction throughout the semester.’
Nate Kornell, in Psychology Today (September 2010 edition) offers the following advice: ‘In Math and Science problems should be mixed together… Mixing problems means that you end up reviewing information you’ve studied before after a spaced interval. It also means that you can’t necessarily solve the next problem the same way you solved the last one–you have to figure out how to approach each problem.’
How can students use the ‘spacing effect’?
- Establish a schedule of self-quizzing that allows time to elapse between study sessions.
- Revisit new material in texts within a day or so, then not again for several days or a week. Then quiz yourself once a month
- Ask themselves how that knowledge relates to what you have subsequently learned
- Study large stacks of flash cards because the more cards you have in your stack, the more time passes before you go through the stack and return to a card you’ve studied before–that is, larger stacks create more spacing.Only stop quizzing yourself on flash cards when all are well mastered. Then revisit each month
- Interleave the study of two or more topics, so that alternating between them requires that you continually refresh your mind on each topic as you return to it
Cited articles and books
Make it Stick by Roediger, McDaniel & Brown
‘Allocating Student Study Time: Massed versus Distributed Practice’ by Daniel Willingham. http://www.aft.org/newspubs/periodicals/ae/summer2002/willingham.cfm
Forget what you know about good study habits. by Benedict Carey. http://www.nytimes.com/2010/09/07/health/views/07mind.html?pagewanted=all&_r=0
Study better: Space it out and mix it up by Nate Kornell, in Psychology Today (September 2010 edition). http://www.psychologytoday.com/blog/everybody-is-stupid-except-you/201009/study-better-space-it-out-and-mix-it
The Problem With “Boot Camp”-Style Learning by Annie Murphy Paul. http://anniemurphypaul.com/2014/06/the-problem-with-boot-camp-style-learning/