The Science of Spaced Repetition: Why It Works and How to Use It

What is Spaced Repetition?

Spaced repetition is a learning technique where you review information at gradually increasing intervals. Instead of cramming everything at once, you space out your study sessions over time.

The result? Better retention with less total study time.

The Science: Why Your Brain Forgets

In 1885, Hermann Ebbinghaus discovered the "forgetting curve"—we forget 70% of new information within 24 hours if we don't review it.

But here's the key insight: each review slows down the forgetting process.

• After 1 review: You might remember for a few days
• After 2 reviews: A week or two
• After 5+ reviews: Months or years

Spaced repetition exploits this by timing reviews right before you'd forget.

How Spaced Repetition Algorithms Work

Modern apps like AnyFlashcards use algorithms (like FSRS) to calculate the optimal time to review each card:

1. You see a card and rate your answer (Easy, Good, Hard, Again)
2. The algorithm calculates when you'll likely forget
3. It schedules the next review just before that point
4. Intervals grow with each successful review

Easy cards might be scheduled for 1 week, then 1 month, then 3 months. Hard cards get reviewed more frequently.

The Research Behind It

Studies consistently show spaced repetition outperforms other methods:

• Cepeda et al. (2006): Spaced practice improved retention by 10-30% vs. massed practice
• Roediger & Karpicke (2006): Testing beats re-reading by 50% for long-term retention
• Pimsleur (1967): Optimal spacing follows a specific pattern for language learning

Medical students using Anki (spaced repetition) consistently outperform those who don't.

How to Implement Spaced Repetition

1. Use a Dedicated App

Don't try to manually schedule reviews—use an app that does it automatically:

• AnyFlashcards (AI generation + spaced repetition)
• Anki (free, powerful, complex)

2. Review Daily

Consistency beats intensity. 15-20 minutes daily is better than 2-hour weekend sessions.

3. Be Honest with Your Ratings

Rate cards honestly. Saying "Easy" when you struggled means the algorithm can't help you.

4. Don't Skip Days

Missing reviews creates a backlog. The algorithm works best with consistent input.

5. Add Cards Gradually

Don't add 500 cards at once. Add 20-30 new cards daily and let the algorithm manage reviews.

Spaced Repetition + Active Recall

Spaced repetition is most powerful when combined with active recall—actively trying to remember before seeing the answer.

This is why flashcards work so well:

• Active recall: Try to answer before flipping
• Spaced repetition: Review at optimal intervals
• Feedback: Immediately know if you're right

Getting Started

Ready to experience spaced repetition? Try AnyFlashcards to:

1. Generate flashcards instantly from your study materials
2. Review with FSRS spaced repetition
3. Track your progress over time

The combination of AI generation and spaced repetition is the most efficient study method available.