But if you add your first repetition very soon, within 24 hours of initial exposure to that information, you’ll strengthen that memory trace just when it’s on the cusp of plummeting over the edge of your memory. And this allows you to go LONGER between each subsequent repetition, basically shifting out and flattening that forgetting curve. 

Add a second, third, and fourth repetition, and that information becomes increasingly ingrained in our working memory.

This is spaced repetition in motion! And it’s so intuitive and powerful that cognitive scientists have been flooding academia with thousands of studies for decades, showing how effective it is as a learning tactic. So, then why isn’t it a core tenet of the modern education system? And why do almost all curricula progress linearly through their subjects without any systematized attempt to help students continuously review older concepts until they’re permanently banked in their brain?

A world without spaced repetition

As proof of how bad that education is without spaced repetition, let me ask you a question: 

How do you say “scarecrow” in Spanish again?

You forgot, didn’t you?

I literally just “taught” you this word less than two minutes ago, yet I’d bet good money that most of you reading this have already completely forgotten it. 

It’s not your fault. Forgetting is simply how the human brain works. If I really wanted you to learn how to say “scarecrow” in Spanish, I should have asked you to repeat espantapájaros again 30 seconds after the first time (while that hard concept was still fresh in your memory) and then again after two minutes, 10 minutes, etc. with each interval getting longer and longer.

The same thing goes for other K-12 subjects and skills far beyond foreign language vocabulary. The list of applications is nearly infinite; spanning nearly all types of academics, professional certifications, and personal development pursuits. In terms of efficiency, spaced repetition eats every other tactic for breakfast.

An effective spaced repetition system

If your goal is to really retain new learning—or help students retain new learning—then what you need is a systematic way to organize the knowledge into a format that allows you to adaptively repeat it at the optimal intervals for your unique pace of learning. Then, spend more time drilling yourself on the harder concepts (espantapájaros) and less time on the easier concepts (hola).

A great vehicle for this exercise are flashcards, which not only allow you to break a subject down into its atomic facts, but also to sort those concepts into “difficult” vs “easy” piles and repeat accordingly. (Digital flashcard apps take things even further with their in-built spaced repetition algorithms.)

In conclusion, spaced repetition can guarantee that your knowledge is constantly building rather than having your brain be a “leaky bucket”. And while it remains an underrated and underutilized learning principle, there are tools at our disposal that can readily help any student of any subject leverage this powerful tactic to learn much more efficiently.

Related:
3 reasons to use spaced repetition
7 strategies to counter student learning loss