Spaced Repetition: The Memory Hack You’re Not Using

Spread out your studying. You will remember more.

• The brain learns best when you review over time, not all at once.
• Recall something just before forgetting, and it sticks longer.
• This method is proven and widely used in education.

Why spaced repetition matters

Instead of cramming all your study sessions into a short period, spread them out. The brain needs time to form connections with the new information before it’s consolidated into long-term memory. This capacity is limited and sleep plays a crucial role. Adjusting your schedule will improve your ability to remember the material and reduce study time.

The forgetting curve illustrates how memory weakens over time

German psychologist Hermann Ebbinghaus concluded in his study _Memory_, that memory retention declines rapidly immediately after learning, with the rate of forgetting slowing down over time.

This is discouraging since studying is a time-consuming activity. Thankfully, spacing out your study sessions changes the curve.

Spaced learning changes the forgetting curve

If you re-study the material retrieval practice at the right time, the curve changes. For every repetition, the curve flattens further as shown in the graph below — meaning you will remember more.

Spacing your study sessions works because the brain needs time to form connections with the new information before it’s consolidated into long-term memory. This happens over hours and days and primarily while sleeping. During sleep the brain replays or rehearses information learned during the day.

How to optimize your schedule for retention

Taking advantage of this is simple: space your study sessions in time. Short study sessions every day are more effective than studying for a whole day once a week. If you have 10 hours to study for an exam, it’s better to study for 1 hour every day for 10 days than to study for 10 hours in one day. Studying for 10 hours the night before an exam might let you pass the exam. But the knowledge will soon fade and you’ll be left with only a fraction of what you could’ve known. By adjusting your schedule to take advantage of the spacing effect, you’re studying for the same amount of time but spaced out.

Use it or lose it

If your aim is to remember forever, you must also repeat forever. Memories you don’t use will at some point fade. But there are ways to remember with minimal effort. Each time you repeat the material, you can increase the gap until the next repetition. This can in time result in considerable gaps between study sessions while still retaining the knowledge.

For every subsequent re-study, you can increase the number of days until the next re-study. Eventually, the long-term maintenance of this memory gets less time-consuming.