The Science of Brainscape

Brainscape’s Confidence-Based Repetition (CBR) technique uses cognitive science to help you learn more efficiently than ever before. CBR’s effectiveness is based on the power of Repetition, Active Recall and Metacognition.

How it works

If you’ve demoed any subjects on Brainscape’s website or mobile apps, you will have noticed that Brainscape is different than most adaptive learning engines. Unlike the usual “multiple-choice” assessment, Brainscape simply asks the user to reveal the answer when s/he is ready to see it, and then to rate his/her OWN confidence in the answer, flashcard after flashcard.

There is a reason we do it this way. The repetitive pattern of Active Recall and Self Assessment (a form of Metacognition) uses a series of proven cognitive science principles to ensure that the learner is acquiring and retaining knowledge as efficiently as possible. Let’s take a look at a few of those core principles used in Brainscape’s adaptive flashcards algorithm.

Brainscape Research

For more information that is not contained in this summary page, check out our research blog, or read our white papers about Confidence-Based Repetition or about Intelligent Cumulative Exposure (our unique language-acquisition methodology).


It’s common sense that the more times you review a concept, the stronger will be your memory of it. This is true no matter how easy or difficult each concept. Indeed, as the ancient Romans said, Repetitio mater studiorum est, or "Repetition is the mother of all learning." Brainscape helps you maximize the number of times you review each concept in a given amount of time, by breaking knowledge down into its smallest building blocks for easy repetition. This repeated mental retrieval of a concept strengthens the memory trace in your brain and trains you to more quickly retrieve that piece of information the next time you need it.


Re-exposure to a piece of information results in a new memory curve (M2) with a stronger initial trace. Note that the slope is the same for both curves despite the differing strengths of initial encoding. (Slamecka & McElree, 1983)

Active Recall

Quizzes or tests that require students to actively recall specific information directly promote learning and help students remember things longer.

From recommendation #5 in the U.S. Department of Education’s practice guide (Pashler et al., 2007)

Truly learning a concept requires the ability to mentally retrieve it from scratch. Unlike multiple choice quizzes where you simply recognize the correct answer, flashcard platforms like Brainscape require active recall of the correct answer. Actively recalling an answer from deep in your brain - and then receiving immediate feedback as you flip the flashcard - is both an engaging and an effective learning method (much more so than multiple choice or skimming your notes!) Perhaps the intuitive knowledge of this phenomenon is what has driven millions of learners to make flashcards over the centuries.


Simply thinking of an answer and then revealing it would be incomplete without the third and most important component of the science of Brainscape: Metacognition. This act of “reflecting upon your own thinking” is invoked when, upon seeing each answer, Brainscape asks you (on a 1-5 scale) “How well did you know this?” Sadler (2006) shows that the act of assessing one’s own judgment of learning is one of the most effective ways to deepen a memory trace; other researchers show that our accuracy of assessing how well we know a topic can even improve over time as a result of practice (Moreno & Saldaña 2004, Kerly & Bull 2008, and Berthold, Nückles, & Renkl 2007).


Confidence-Based Repetition

These combined concepts of Repetition, Active Recall, and Metacognition work together to create Brainscape’s unique process of Confidence-Based Repetition (CBR). CBR acts essentially as your personalized knowledge stream, where bite-sized concepts are repeated one after another, in Question/Answer pairs, and then re-entered into the repetition queue in intervals based on your confidence in how well you know them. Low-confidence items (e.g. the 1’s and 2’s) are repeated more often until you upgrade your confidence to higher levels.

Bahrick & Phelps (1987) show that the optimal interval of spaced repetition is the longest amount of time before you would have otherwise forgotten the concept. Brainscape essentially ensures that your pattern of repetition will be as close to this interval as possible. We are optimizing the practice of spaced repetition that educators have been recommending for decades.

All told, Brainscape is the only mainstream web/mobile flashcard platform that applies the latest in cognitive science principles to ensure the most effective learning experience possible. Please feel free to read our CBR white paper and/or check out the Brainscape Blog to learn more.