Spaced Repetition

So what is the solution to the forgetting curve (hint: use the spacing effect and the testing effect…)? You got it… Spaced Repetition with Active Recall. Now we first came across Spaced Repetition in  Buzan (1988: 4-43). Buzan recommended reviews at 1 day, 1 week, 1 month and 4 months. but Evernote had not been invented back then (we barely had the PC and Bill Gates only had $1bn) so it was not easy to do. These days educators recommend the practice (the illustration below is from the E-Learning Council). Unfortunately, the scientific research grounding these recommendations is not easy to track down because most of the studies employ only two ‘study events’. One possible explanation is that they are too lazy to do any more. Fortunately, you can try it out for yourself and see how effective it is.

So here is the idea:

If you review (actively review, remember) information just at the point you are about to forget it then firstly, you strengthen your memory of that information and secondly, the subsequent forgetting curve is less severe; it will take you longer to forget it. Furthermore, at each review, it will take you less time to refresh your memory. Here is a graph (based on an initial 1 hour learning session) illustrating the point. Or a cross-section of a tsunami about to flatten Hawaii, I’m not sure which:

Note that it takes you less time to review the information at each review. So, for example, at the 3rd review, you are only spending 2-4 minutes on review. This is important to the cost-benefit of reviewing as the following table shows:

Strategy Initial Study(m) Review(m) Total (m)
Spaced Repetition 60 10+5+4 79
Cramming 60 50 110

The cramming strategy spends 60m learning the material, then completely forgets it and spends 50m re-learning it again. In other words, the cramming strategy takes more time overall … and, of course, with the cramming strategy, there is not much to show for it 30 days later. If you are serious about developing your expertise in an area, then it is not the way to go.

How does Revunote help?

  1. It drives the review cycle for you (Spaced Repetition).
  2. It’s design encourages you to recall the information before you check with Evernote (Active Review).

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  • Buzan, T. (1988) Make the Most of Your Mind, London: Pan Books

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