Flashcard

An English-speaking student learning the Chinese word 人 (rén, person or people) may write a card with the following sides.

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.

Additionally, spaced repetition software has been developed to aid the learning process through a virtual format as opposed to merely a physical one.

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.

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.

There is a wide range of software, including open source and online services, available for creating and using virtual flashcards as a learning aid.