We all want to find the most efficient ways to study, finding that balance between time spent and knowledge retained. The Leitner system, with many variations, is a commonly used technique using flashcards that was proposed by the German science journalist Sebastian Leitner in the 1970s. It is a simple system that uses the principle of spaced repetition, where cards are reviewed at increasing intervals as the material is learned.
Suppose there are 3 boxes of cards called “Box 1”, “Box 2” and “Box 3”. The cards in Box 1 are the ones having questions that the student often makes mistakes with, and Box 3 contains the cards that they know very well. They might choose to study the Box 1 cards once a day, Box 2 every 3 days, and the Box 3 cards get quickly run through once a week. If they look at a card in Box 1 and get the correct answer, they “promote” it to Box 2 as, since they know it, it can be removed from daily review. A correct answer with a card in Box 2 “promotes” that card to Box 3. If they make a mistake with a card in Box 2 or Box 3, it gets “demoted” to the first box, which forces the student to study that card more often again.
As the student moves through the course, they simply jot down new concepts / problems on a new card after each class and toss it into Box 1 to be added to the list of concepts that needs to be learned. As the student learns it, it falls out of regular study.
The Leitner system ensures that the student focuses most of their efforts on the most difficult flashcards (or, at least, those that they are having problems answering), which remain in the first few groups. The result is, ideally, a reduction in the amount of study time needed as, once a concept is known it promotes itself out of regular study into a category where you just check your memory on an infrequent basis.
