How does Brainscape's spaced repetition algorithm work? (i.e. Confidence Based Repetition)

You probably really enjoy studying in Brainscape, and maybe you wonder how our algorithm works or why you see certain cards more frequently than others.  Are you wondering how this helps you learn?  We've provided a bit more detail for those interested in the brain science and learning connection in Brainscape.

How does the algorithm work?

What Brainscape calls “Confidence-based Repetition” (CBR) is our proprietary algorithm for using spaced repetition to help Brainscape users master and retain knowledge in the most efficient manner possible. 

Without sharing all of the secret mathematical formulas, here is how it works in general:

1. Brainscape shows you a question

2. Brainscape asks you try to answer the question (in your head), which uses a mental skill called active recall

3. Brainscape asks you to rate how well you knew the answer on a scale of 1-5, which uses a form of mental reflection called metacognition and allows you to implement adaptive learning into your routine

4. Brainscape uses your confidence rating to determine how soon to repeat that card again (i.e. spaced repetition)

As you continue studying, Brainscape will continue to optimize the interval between each card’s repetition. As a general rule of thumb, this is what you can expect based on how you rate a card:

• 1 (a few minutes);
• 2 (10+ minutes);
• 3 (hours);
• 4 (days);
• 5 (weeks or months)

The actual interval that cards repeat depends on how much you're studying, and how stale your cards are.  The more stale cards you have in your study mix, the more likely you will be to see those stale cards repeated rather than seeing new cards.

Your specific pattern of repetition is determined by various factors:

(i) how many decks or classes are in your study mix;
(ii) your previous study patterns;
(iii) the time since the last time you studied each card; and
(iv) the number of previously rated cards in the 1-5 confidence buckets.

Brainscape is careful to avoid overwhelming you with too much new content until you have gained sufficient confidence in the cards you’re already studying. But we are also careful not to repeat cards *too* quickly while they’re still so fresh in your mind.  Our system uses a combination of cognitive science research, human judgment, and intelligent software to provide an increasingly optimal repetition patter that maximizes your learning speed and retention.

Now you know!  

Still have questions and can't find the answer?  Be sure to email our Tech Support Team ([e-mail]). 

If you'd love to vote for a new Brainscape feature, see what others are requesting, or get a sneak peek at features in our pipeline, please check out Brainscape User Feature Requests Forum!  Please choose to Sign in with Brainscape (if you are commenting/requesting a new feature) so any feedback is tied to your account.  Or you can even access the tool from our web/mobile menus which won't require you to login separately. 

(Hint:  to save time, search first to see if your desired feature is already in the list so you can just vote/comment.)

And for more FREE study advice don't forget to check out the Brainscape Academy.