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Spaced repetition

Spaced repetition

Spaced repetition using flashcards is one of the most effective methods to memorize things. If you want to learn more about it, you can start on article on Wikipedia or check out this wonderful comic strip from Nicky Case.

Recall level

Every card detected in your notes has a so called “recall level” associated with it which indicates how well you remember it. It also represents the number of days after which it will be queued for review again.


When you are testing yourself, the recall level changes based on how well you remember the card. The theory is simple - if you remember it well the recall level goes up, otherwise it goes down.

Recall uses a simple algorithm and multiplies the current recall level by a constant and there’s a constant defined in your configuration for each of the review results. By default, these constants are 2, 1 and 0.5, which in practice means that

  • if you click Remembered, the recall level will be doubled;
  • if you click Forgot, the recall level will be halved;
  • and if you click Struggled, the recall will stay the same.

Alternative setup

Some articles on spaced repetition recommend that if you forget a card, its recall level should go back to 1 and it should appear in your review the next day. If you want to use this approach, it can easily be achieved with the following configuration:

Setting usedValueMeaning
Multiplier for Rembembered2Recall value will be doubled
Multiplier for Struggled0.5Recall value will be halved
Multiplier for Forgot0Recall value will be set to 1 (the minimum)

Naturally, other values for the constants are also possible so you can fine tune your algorith as you see fit. The above is just one of the alternatives.

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