Flashcards specifically exercise the mental process of
active recall: given a question, one must produce the correct answer. However, many have raised several questions regarding optimal usage of flashcards: how does one precisely use them, how frequently does one review, and how does one react to errors, either complete failures to recall or partial mistakes? Various
systems have been developed, mostly based around
spaced repetition, the technique of increasing time intervals between reviews whenever a card is recalled correctly.
Spaced repetition Spaced repetition is an
evidence-based learning technique which incorporates increasing time intervals between each review of a flashcard in order to harness the
spacing effect. Spaced repetition is an evidence-based learning technique which incorporates increasing time intervals between each review of a flashcard in order to harness the spacing effect. Newly introduced and more difficult flashcards are shown more frequently, whereas older and less difficult flashcards are shown less frequently. The use of spaced repetition has been shown to generally increase one's rate of learning. Although the principle is useful in many contexts, spaced repetition is commonly applied in contexts in which a learner must memorize a large number of items and retain them in long-term memory. It is therefore often used in
vocabulary acquisition amidst second language learning. Additionally, spaced repetition software has been developed to aid the learning process through a virtual format as opposed to merely a physical one.
Leitner system , correctly answered cards are advanced to the next, less frequent box, while incorrectly answered cards return to the first box for more aggressive review and repetition. The
Leitner system is a widely used method of efficiently using flashcards. Originally proposed by the German science journalist
Sebastian Leitner in the 1970s, it is a simple implementation of the principle of spaced repetition where cards are reviewed at increasing intervals. In this method, flashcards are sorted into groups according to how well the learner knows each one in the Leitner's learning box. The learners then try to recall the solution written on a flashcard. If they succeed, they send the card to the next group. If they fail, they send it back to the first group. Each succeeding group has a longer period of time before the learner is required to revisit the cards. In Leitner's original method published in his book (
How to learn to learn), the schedule of repetition was governed by the size of the five partitions in the learning box, which were , respectively. The learner only reviewed some of the cards in a section whenever it became full, subsequently moving them forward or backward depending on whether they remembered them.
Software Anki to review a mathematical formula. First, only the question is displayed. Then the answer is displayed too, for verification.There is a wide range of software, including
open source and online services, available for creating and using virtual flashcards as a learning aid. ==History==