The Benefits of Spaced Repetition

2021-01-14

Through a combination of research and trial and error, educators have learned a lot about how people learn. A couple of years ago I mentioned the idea of spaced repetition. This is a technique where learners review material after some time. It makes learning more efficient both in terms of time to learn something and the length of time knowledge of the material is retained.

What is spaced repetition?

Spaced repetition began with the use of flashcards. Users use the cards as a sort of test. In learning a natural language, for instance, the card might have a term in the new language on one side and the meaning on the other. The learner then looks at the new word and the goal is to remember the meaning (or vice versa). One way to use the cards is to go through them over and over at once. It turns out to be more effective to go through them once or twice, then wait and go over them again at a later time. That is the "spaced" part of spaced repetition.

When I teach a Learning Tree course such as our Introduction to Cyber Security, I suggest that participants use the review questions at the ends of the chapters as a spacing tool. I ask them to wait to go through those questions until a day or two after the class is over. This helps them to recall the course content longer.

Some resources for exploring spaced repetition

Here are some resources for exploring the research and practice of spaced repetition:

https://www.lifehack.org/851026/spaced-repetition discusses how to use spaced repetition as a self-learner. It delves into the history of spaced repetition as well as practical application. Additionally, it provides resources for further exploration.
https://www.scotthyoung.com/blog/2019/02/15/memory/ Scott H. Young the author of Ultralearning talks about brain function, learning, memory, and how spaced repetition fits into the picture. He clearly applies this knowledge in his own learning as he explains elsewhere in his blog and in Ultralearning.
https://collegeinfogeek.com/spaced-repetition-memory-technique/ uses a video along with the text to explain how spaced repetition helps aid retention. His good discussion of the "forgetting curve" highlights why we forget the things we learn and how to overcome that.
https://www.pnas.org/content/116/10/3988 This scholarly article from the U.S. National Academy of Sciences talks specifically about the duration of the spacing of spaced repetition activities. It seems that dynamic spacing may be better than fixed spacing. That is longer spaces between the repetition of concepts we seem to have learned versus shorter spacing between repetitions of the content we have not.
https://fs.blog/2018/12/spacing-effect/ also addresses the spacing between exposure to materials
https://www.scotthyoung.com/blog/2014/11/07/srs-for-concepts/ Scott H. Young explains that spaced repetition is not a solution to all learning all types of content. He explains when to use it.

Spaced repetition is a valuable tool to accelerate learning and increase retention. Not all learning materials deploy it as part of the content. If not, the resources I shared above should help you implement it yourself in a way that works for you. Choose the way that suits you: flashcards, sticky notes, software, or some other method. I hope it helps you retain material as it has helped me.

Written by John McDermott

John McDermott, CPTD, started his work in computer security in 1981 when he caught an intruder in a system he was managing. In recent years his consulting has included security consulting for small businesses. He is Security+ and CCP certified. In his 30 years with Learning Tree John has written and taught courses in programming, networking and computer security. He is the co-author of Learning Tree’s course System and Network Security: A Comprehensive Introduction. John is currently a learning and development consultant in northern New Mexico. He lives in a house made of earth with his wife, who is an artist.