Fig. 1

Comparison of exposures to a knowledge with spaced-repetition and traditional techniques.

This diagram illustrates the early focus of traditional learning techniques on amassing practice, which creates an initially strong memory that ultimately decays without further revision. By comparison, spaced-repetition is known to effectively distribute meaningful practice across time to reinforce learning and slow the decay of memory, promoting long-term retention [20]. Individual flashcards are personally scheduled based upon user ratings of difficulty, with the interval between revision instances reduced for more difficult flashcards, improving the retention of knowledge. Conversely, easier flashcards are given longer intervals to both increase time efficiency and ensure meaningful challenge in revision