Overlearning in spaced repetitions: positive or negative for long-lasting memory?

Neuroscience, Psychology, and Health
1

Research shows that spaced repetitions (eg. 5 repetitions distributed in day 1, 2, 4, 8, 16) produces longer-lasting memories than massed repetition (eg. 5 repetitions all concentrated in a single day, even if it’s the last day, day 16).

This brought to the common belief that the best moment to repeat (preferably with “free recall”) an information is just before forgetting it.

However, I see much confusion about whether adding extra (or anticipating) repetitions (at the cost of more time spent) has a positive or negative effect.

For example, suppose to start in day 1 and finish in day 16 with these different plans:
a) repetitions “just before forgetting”: day 1, 2, 4, 8, 16 (total of 5 repetitions)
b) anticipated repetitions: day 1, 1.5, 2.5, 4, 6, 9, 12.5, 16 (total of 8 repetitions)

In the SuperMemo intro, I read:
“You will be surprised to know that it is often better to avoid repetition in order to build long-term memory. You may be annoyed that SuperMemo forces you to go against your own intuition. However, this is how your memory works!”

Are we sure that it’s true? is there any scientific evidence that “b)” costs more time and it even generates SHORTER lasting memory after day 16 than “a)”?

I’m skeptical… since I never saw scientific evidence about what the SuperMemo intro stated and my good sense and articles that I read on the web claim that overlearning is positive (“Tests for retention given at set intervals after training indicated that the greater the degree of overlearning, the greater the retention.”, source this scientific paper: http://andrewvs.blogs.com/usu/files/effect_of_overlearning_on_retention.pdf)

What do you think about overlearning?
is the cited SuperMemo statement true or false?

2

I just finished reading a fantastic book called “Make It Stick” by Brown, Roediger and McDaniel. The book pulls together a lot of the latest research in cognitive science dealing with remembering and learning. According to the research they present, the harder you have to work to retrieve a memory, the better you do to imprint this memory’s pathway into your brain. The closer you wait to forgetting something before recalling it, the better you will ultimately know it.

It would follow that overlearning would actually decrease what are called “desirable difficulties” and thus decrease the degree to which a memory has been implanted into your brain. If you’re repeatedly learning something at short intervals but never have to work very hard to retrieve it, you’re either going to spend a lot of wasted effort to put something firmly into your long-term memory or you’re not going to get it there at all (at least to the point of permanently sticking).

The authors of the book (two of them cognitive psychologists) actually say that many of what are turning out to be ideal learning methods are quite counter-intuitive.

Unfortunately I “read” the book as an audiobook so I don’t have any direct footnotes with their primary sources. Highly recommend the book though!

3

Isn´t it possible to do a self-experiment memorizing two lists similar in lenght and dificulty and then using a different repetition plan for each of them?. After some time (maybe 16 more days?) one could check how many elements is able to remember from each list.

4

somnambulyst, too bad that you don’t remember the sources of the book because the researchers who did the meta-analysis that I cited collected 15 scientific studies about overlearning and retention and concluded that overlearning produces a positive although short-term enhancement in retention:

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Even a newer although single study arrived to the same conclusion that overlearning brings to a positive although short-term enhancement in retention:

Abstract
Once material has been learned to a criterion of one perfect trial, further study within the same session constitutes overlearning. Although overlearning is a popular learning strategy, its effect on long-term retention is unclear. In two experiments presented here, 218 college students learned geography facts (Experiment 1) or word definitions (Experiment 2). The degree of learning was manipulated and measured via multiple test-with-feedback trials, and participants returned for a final cued recall test between 1 and 9 weeks later. The overlearners recalled far more than the low learners at the 1-week test, but this difference decreased dramatically thereafter. These data suggest that overlearning (and its concomitant demand for additional study time) is an inefficient strategy for learning material for meaningfully long periods of time. Copyright © 2004 John Wiley & Sons, Ltd.

I also think that every memory athlete believe that reviewing their peg list or loci every single day for 3 months before a championship brings to a better performance than reviewing them only just before forgetting it, even if in both cases the last review is immediately before the championship.

No study that I found concluded that overlearning ruins long-term memory or don’t enhance short-term memory of the overlearned material as your book stated, if I understood your words well.

In short words, what I found is:
A) “spaced repetitions” (just-before forgetting, eg. on day 1, 3, 7) is better than “massed repetitions” (eg. on day 5, 6, 7) for long-term retention and likely for short-term retention too
B) “spaced repetitions” + overlearning (eg. on day 1, 2, 3, 4, 5, 6, 7) is better than “spaced repetitions” (eg. on day 1, 3, 7) for short-term retention, with a decay of the advantage over time until a zero advantage
(tests always after day 7)