Spaced repetition (SR) is a method for reviewing material at regular intervals. The idea behind SR is to improve long-term memorization and retention by spacing out review sessions over time. This method helps you remember information before it slips from memory and supports its storage in long-term memory.

Explore our video guide to spaced repetition:

When studying cards, Anki Pro prompts you to rate how well you know each card. The better you understand a flashcard, the less frequently it will appear. Flashcards marked as “Hard” will be displayed more often than those marked as “Easy”.

You can select the number of new cards you want to study each day in the deck settings. Alongside the new cards, you review the flashcards you've already learned.

During your study session, you first review the cards you've practiced previously and then tackle a small batch of new cards. Once you've completed all the cards scheduled for the day, the app will indicate when the next batch of cards will be ready for review.

Intervals between revising cards are essential in SR due to the workings of human memory. SR takes advantage of the psychological principle known as the spacing effect, which indicates that information is better retained when learning is spaced out over time rather than cramming it all at once. If immediate card revision is necessary, consider switching to the general repetition algorithm.

Note: SR aids long-term studying. Don't anticipate immediate results within a day or two. However, once you've incorporated flashcard studying into your daily routine, you'll notice improved information retention, ultimately leading to reduced study time overall.

Mapping the likelihood of successfully recalling a piece of knowledge against the number of days since learning it reveals a descending curve, represented as the red line in the image below. This line is known as the forgetting curve.

Recalling pieces of information can alter the forgetting curve, preventing its descent. Rather than attempting to repeat a flashcard multiple times within a single day, it's more effective to practice it over course of days, weeks, and months. This practice of spacing out repetitions is what makes SR such an effective technique.

In the image below, you can observe how recalling information modifies the forgetting curve and aids in information retention:

Spaced repetition manages when and how often you need to revise flashcards. It is highly practical because the interval between consecutive practice sessions expands each time you revise. After reviewing a card for the first time, the next time you will see it in is a day, after the second review you will see the card in 2 days, after the third in 4 days, and so on. After every revision, it takes more and more time to see the card again, eventually extending to months before you encounter it once more.

Scientific research has proven that SR is a significantly more effective learning technique than reading material multiple times within a short period.

To check how well you remember something, you have four choices:

AnkiPro uses your responses to automatically schedule the next review of the card.

Here's how your responses determine when you'll see the card next: