The Science Behind Spaced Repetition Systems

You study for hours and forget everything in days? The problem isn’t effort — it’s timing. The Spaced Repetition System (SRS) solves this with over a century of cognitive science. Discover how Affex uses this algorithm to beat Anki and Noji.

Table of Contents

• The Forgetting Curve: The Invisible Enemy
• Hacking Memory with Spaced Repetition
• How Affex Flashcards Perfect the Algorithm
• The Results Speak for Themselves
• Affex vs. Anki vs. Noji: A Direct Comparison
• Frequently Asked Questions
• Conclusion

The Forgetting Curve: The Invisible Enemy

In 1885, Hermann Ebbinghaus discovered that your memory follows an exponential decay curve. Without review, you forget:

• 50% in 1 hour
• 70% in 24 hours
• 75% within a week

This is the Forgetting Curve. It explains why cramming works for the exam but fails afterwards. Your brain discards unreinforced information as “noise.”

Hacking Memory with Spaced Repetition

Spaced repetition combats the Forgetting Curve: you review at the exact moment before forgetting.

Each successful recall sends a signal to your brain: “This is important. Keep it.”

Typical schedule:

• Review 1: +1 day
• Review 2: +3 days
• Review 3: +7 days
• Review 4: +21 days

With each recall, the interval increases. Information migrates from short-term memory to permanent long-term storage.

How Affex Flashcards Perfect the Spaced Repetition Algorithm

Anki and Noji popularized SRS flashcards, but have problems: Anki is complex (high learning curve), Noji is too basic.

Affex uses the SM-2 algorithm (SRS gold standard) with modern, friction-free interface.

1. Smart Scheduling

Affex calculates, doesn’t guess. Based on your assessment:

• Easy card? Review in 1 month
• Hard card? Review tomorrow

You spend time only on what you need. Result: the same mastery in 30-50% less time.

2. Integrated Active Recall

Unlike re-reading or highlighting (passive methods), Affex forces your brain to retrieve the answer before showing it. This mental effort creates permanent neural connections.

3. Mobile-First Without Friction

Study during breaks in your day: bus, line, waiting room. No complexity of “preparing” a session. Consistent daily habit = long-term retention.

The Results Speak for Themselves

Research on spaced repetition proves:

• Significantly higher long-term retention vs. massed study, confirmed across 254 studies (Cepeda et al., 2006 — Psychological Bulletin)
• 30-50% less time for the same mastery
• Permanent knowledge that lasts years

Affex vs. Anki vs. Noji: A Direct Comparison

Feature	Affex	Anki	Noji
SRS Algorithm	SM-2 (optimized)	SM-2	Basic
Learning Curve	Low	High	Low
Mobile-First	✅	⚠️	✅
Gamification	✅	❌	⚠️
Structured Paths	✅	❌	❌
Cloze Deletion	✅	✅	❌
Native Anki Import	✅	✅	⚠️
Pomodoro Timer	✅	❌	❌
True Cross-Platform	✅	✅	⚠️
Free Tier	✅	✅	✅

Frequently Asked Questions

What is the SM-2 algorithm?

Super Memo 2, developed in 1987. Calculates optimal intervals based on your performance on each flashcard. It’s the SRS gold standard used by Affex, Anki, and other apps.

Is Affex better than Anki?

Depends on your profile. Anki is powerful but complex (great for advanced users). Affex balances power + simplicity, ideal for those who want to start quickly without complicated configurations.

How much time per day do I need to study?

15-30 minutes daily is sufficient. Consistency beats volume. SRS ensures you review only what’s necessary.

Does spaced repetition work for any subject?

Yes. Languages, medicine, law, programming, history — any memorization-based content benefits.

Can I use physical flashcards with SRS?

Yes, with the Leitner Method (boxes). But apps automate calculations, notifications, and adjustments, saving time and increasing precision.

Conclusion

Studying the traditional way is renting knowledge. With spaced repetition, you own permanent knowledge.

Whether for medicine, languages, or certifications, Affex transforms studying into predictable scientific system. For more ideas on how to implement this, see our guide on 11 practical ways to use spaced repetition.

Download Affex and stop forgetting →