The spacing effect

In the field of psychology the spacing effect refers to the finding that information, which is presented over spaced intervals is learned and retained more easily and more effectively.

In particular it refers to remembering items in a list. You can study them in fewer times over a long period of time (spaced presentation) or repeatedly in a short period of time (massed presentation). It was found that spaced repetition is much more beneficial both time-wise and retention-wise.

In simple words:

If your reviews are farther apart in time you will benefit much more than when the repetitions are close together.

An example for the spacing effect

Let’s take a practical example. Let’s say you have freshly learned something:

In method 1 (massed repetition) you repeat it immediately ten times in a row.

Do you think it helped you to remember it longer? Probably not.

In method 2 (spaced repetition) you make the first repetition after say 1 hour, the second after 5 hours, the third after 1 day, the fourth after 3 days, and so on … until finally the tenth repetition after about eight months.

All experimental findings conclude that method 2 is much more effective.

Although you spent exactly the same amount of time for the repetitions in both cases it is very likely that you will have forgotten the piece of information with method 1 after about 1-2 days, whereas using method 2 (spaced repetition) you will still know it after almost a year.

This fact was first found by the German psychologist Hermann Ebbinghaus. He published his findings in his book “Über das Gedächtnis. Untersuchungen zur experimentellen Psychologie (Memory: A Contribution to Experimental Psychology)” in 1885.

The spacing effect was confirmed in many different memory tasks such as recognition, frequency estimation, free recall and cued recall.

The spacing effect is extremely powerful and robust. That means:

  • It works for many types of learning.
  • You can depend on it.

In short: it just works!

Why is the spacing effect effective? How can you apply it in your studies?

Many experiments were performed on this question and the following simple fact was found:

The closer you are to forgetting a piece of information the more you will profit from reviewing.

It is important, however, that you don’t wait too long. After the point of forgetting it is almost as difficult to relearn the piece of information as the first time you learned it. That’s why it is necessary to know exactly when you will forget a piece of information. Impossible? No. The spaced repetition software Flashcard Learner does all the work for you. It adapts to your learning and forgetting patterns and calculates exactly when you are most likely to need a review before your forget a flashcard.

Why does the spacing effect work?

Why does the spacing effect work? All experiments conducted suggest that the spacing effect is a fundamental property to all biological life forms. Spaced repetition works on all tested animals, not just for humans. The spacing effect works, because that’s how the nerve cells in our bodies store information. It is a physiological fact.
Recent experiments in rats have found that the spacing effect has a clear neuro-physiological basis: Sisti et al. (2007) showed that neural longevity in the hippocampus of rat brains improved significantly with spaced repetition. (The hippocampus is a region in the brain, which is important for long-term storage of information.)

Despite of the well researched facts of the spacing effect for over a century the traditional educational practice largely ignores it. With detrimental effects: how much do you still remember from your high-school or university time?

You can apply the spacing effect and improve your learning and your performance in school simply by learning the material and reviewing at regular and increasing intervals. Like that you will know more and forget much less
.
The best way however to improve your learning is to use a spaced repetition software, which keeps track of your learning progress and calculates exactly when you are about to forget a piece of information. That’s when you profit most from the repetition.

References:
H.M. Sisti, A.L. Glass, T.J. Shors: Neurogenesis and the spacing effect: Learning over time enhances memory and the survival of new neurons. Learn. Mem. 2007;14(5):368-75.