The Leitner Box or Leitner System is a flash card driven spaced repetition learning system developed in the 1970s by German journalist Sebastian Leitner. The Leitner Box itself is a physical box of index cards, divided into no fewer than 3 compartments, but potentially with as many as 7 or 8 compartments, scaled according to how much time a student has to practice learning a subject (such as a foreign language) before they will need to be prepared to exercise that subject fluently. Each compartment is defined according to an interval of time, indicating how frequently its contents are to be reviewed and checked for errors: a day, two days, a week, two weeks, and so on.
To begin, all flash cards are placed in the compartment oriented nearest the student. Every time they get an answer right on a flash card on the first try, the student moves that card to the second compartment away from them. They cycle through the entire set of cards, until every correct answer is sorted into the second compartment, and every other card - those which were not answered correctly on the first attempt - remain in the first compartment.
The following day, or at some other short interval of time, the student goes through what cards remain in the first compartment. Correct answers sort into the second compartment. Next, the student goes through all cards in the second compartment of the box. Anything answered correctly on the first try is sorted into the third compartment away from the student. Anything answered incorrectly, however, reverts all the way back to the first compartment, where answers in error are kept.
The student continues to review the first compartment daily. The second compartment is reviewed on alternating days, rather than consecutive days. The third compartment is reviewed weekly, and subsequent compartments have still longer time intervals for review. Only when all cards in the entire box remain at the farthest-away compartment for consecutive practice sessions, is the learning material considered securely memorised.
Spaced repetition is arguably the most effective method for gaining a large amount of new vocabulary in a language, especially specialised vocabulary that suffers infrequent real-world encounters among native speakers. As such, the Leitner Method has very high utility for extending one's skills in a foreign language in which one already has a solid foundation in grammar and syntax. The Leitner Method fares comparatively poorly for handling knowledge which requires a deeper and more dynamic response than what can tidily fit on a flash card, for obvious reasons.
For a somewhat similar system which documents skill gain as additive progress over time, but which does not revert materials for more frequent review when errors are made, see Junkill's "Solid Red" Method on the flash cards node.
Leitner's system can be extended into multiple simultaneous subjects in an organised way, through the use of colour-coded flash cards, and it can be made accessible for blind users through the use of a Braille slate, which tends to perform well on index cards. Craft scissors that create different shaped scalloped edges can also be used to trim index cards, to create a tactile equivalent of colour-coding. As such, this form of spaced repetition is particularly more accessible than flash card mobile applications and other software, which often do not offer any text-to-speech or recorded speech option for blind users.
Iron Noder 2022, 15/30