What is spaced repetition and how does it decide what to show me?

Spaced repetition is a scientifically proven study technique where cards are scheduled for review at increasing intervals based on how well you know them. Flashycards builds on this with a proprietary algorithm backed by learning science and machine learning. The system tracks how well you know each card and predicts when you are most likely to forget it. Cards you find tricky appear more frequently, while cards you know well are spaced further apart. After each session, Flashycards calculates your next best study date — so every session is tailored to you and you spend your study time where it matters most.