Spaced Repetition System

A problem:

In college, I did so much right: I read, I paid attention, I took notes. I learned so, so very much in college — and was excited about it!

And now I've forgotten nearly all of it.

Sometimes I flip through my college books — tomes filled with underlinings and ecstatic marginalia ("CAN YOU BELIEVE HOW COOL THIS IS?!") — and am surprised to realize I have no idea what the book is even about.

Almost all the things I spent so much time learning — gone! Evaporated!

This isn't unique to me. Our brains aren't designed to retain information learned in school. We're leaky buckets.

To talk this way is, to be clear, a minor heresy in education. We educational reformers aren't supposed to care about knowledge — after all, didn't William Butler Yeats say:

Education is not the filling of a pail
but the lighting of a fire.
–William Butler Yeats

Well, actually, he didn't (the quote is a rehashing of Plutarch). But whoever said it, it gets at something important — that education is about inspiration, and heat, and beauty!

But education is also about knowledge. Knowledge of the world fuels the fire of learning. Education, then, is about the filling of a pail and the lighting of a fire.

If education is fire, then knowledge is kerosene.

And our buckets leak. 

But they don't have to.

A hundred thirty years ago, an German experimental psychologist painstakingly uncovered the algorithm for human forgetting. If we plug a few variables into a simple equation (the "forgetting curve"), we can now predict how long any piece of information will be remembered.

Better, knowing this algorithm lets us fix the problem. We can hack forgetting. 

Our basic plan:

Lock in a core of knowledge by using a spaced repetition system, like Anki or SuperMemo.

Only put in those pieces of information that

  1. are most crucial for long-term understanding, or
  2. are most delightful for the student.

Make cards for students, and help each student to do this on their own.

Give a brief time each day (5 minutes) for students to quiz their decks.

The goal:

Adults who love learning more because they're confident what they're learning now will stick with them long-term. 

Adults who understand the cognitive limitations that come with having a human brain, and who know the science of punching through those limitations.

Adults who feel they can strive toward the ideal identified by playwright Richard Foreman:

I come from a tradition of Western culture in which the ideal (my ideal) was the complex, dense and "cathedral-like" structure of the highly educated and articulate personality — a man or woman who carried inside themselves a personally constructed and unique version of the entire heritage of the West.
– Richard Foreman

If you walk into a classroom, you might see:

Teachers and students discussing which few pieces of a history, math, or science lesson they'd like to remember forever.

A student standing at one of the classroom computers to do their daily five-minute flashcard quiz on whatever bits of knowledge the algorithm tells them they're about to forget. 

specific questions:

At what age should we transition from Leitner boxes (filled with handmade flashcards, and which follow a much less exacting repetition pattern) to a computerized deck?

Once we make the transition, should we scan in the Leitner cards, and incorporate them into our computerized SRS?

(This idea is currently in beta! If you've thoughts on how to make it better, please shoot an e-mail to Brandon at

Related elements:

Cognitive Psychology
Knowledge is Necessary
Leitner Boxes

To Learn More:

If you haven't yet read Gary Wolf's now-classic article "Want to Remember Everything You'll Ever Learn? Surrender to This Algorithm", you'll want to! It explains the science (and story) behind spaced repetition systems.

Gabriel Wynne's powerful book Fluent Forever: How to Learn Any Language Fast and Never Forget It is basically a path to weaponizing spaced repetition (and linguistics) to master a new language. (Our schools will be using its method in the upper years.)