

Chapter 1
The man who forgot on purpose
Chapter 2
The physical brain under construction
Chapter 3
From cardboard boxes to supercomputers
Chapter 4
Spaced repetition in the wild
Ch 3 · From cardboard boxes to supercomputers

duolingo Flashcards advance through the compartments with correct answers but return to Box 1 after mistakes, automatically sorting them by difficulty.
Quiz
In which decade did German science journalist Sebastian Leitner popularize his famous cardboard box flashcard system?
Quiz
In the classic Leitner system, what happens to a card in Box 4 if you answer it incorrectly?

duolingo Paper memory experiments in 1985 laid the foundation for modern digital learning algorithms.
Quiz
Which classic Woźniak algorithm is still used as the foundational math behind many modern flashcard apps?
Quiz
What was the name of the pioneering spaced repetition software created by Piotr Woźniak in 1987?
Fun Fact
Amstrad PC 1512: Piotr Woźniak coded the very first digital version of SuperMemo on an Amstrad PC 1512, which was quasi-legally imported into Poland from Germany in 1987.
Quiz
What does the Japanese word Anki, which inspired the name of the popular flashcard software, translate to in English?
Quiz
Who created the initial version of the open-source flashcard program Anki in 2006?
Glossary
leitner system (noun)
A study method where flashcards are sorted into physical compartments based on recall accuracy. German journalist Sebastian Leitner introduced this card-sorting technique in 1972 to organize learning schedules.
A study method where flashcards are sorted into physical compartments based on recall accuracy. German journalist Sebastian Leitner introduced this card-sorting technique in 1972 to organize learning schedules.
Quiz
What does the modern machine-learning-based spaced repetition scheduler FSRS stand for?
Quiz
Compared to older algorithms like SM-2, what is the primary benefit of using a machine learning model like FSRS?
