Spaced Repetition

Spaced repetition is a technique for reviewing information at increasingly longer intervals. It's currently our best answer to how can I spend the least amount of time studying and get the maximum benefit? The greatest thing about spaced repetition is that it let's you have your cake and eat it, too - you can spend less time studying and achieve greater memory retention.

So what's the catch? Spaced repetition is the anti-cramming solution. It requires steady commitment over time. It won't help you prepare for a test the night before. The good news is that only a very small time commitment each day can yield results far superior to cramming information over one or two sessions.

For a short, CleverDeck-branded intro to spaced repetition, check out this video we made.

How It Works

The idea behind spaced repetition is incredibly simple. For explanation's sake, imagine that you are learning the Spanish word for dog.

A bad way to learn dog would be to review it three times today, three times tomorrow, and then look it up again when we eventually forget it.

A better approach would be to review dog today, then again tomorrow, then three days after that, then one week after that, then one month after that. Every time we review dog, we wait longer until we review it again. Whenever we are on the verge of forgetting it, we refresh our memory with a quick review.

That's spaced repetition. Easy, huh?

A spaced repetition system, then, is a program that predicts when you will forget information and plans review intervals for you.

Incorporating Performance

Now imagine that we don't remember dog every time we see it. What if, on our third review, we've completely forgotten it?

By telling a spaced repetition system whether or not you remember things, it can be smarter about scheduling those review intervals. If you forgot something, you should see it again soon. If you remember it, you're safe to wait longer.

And by tracking and evaluating your entire history of forgetting and remembering something, the system can be even smarter about deciding when you should review it again. Do this for lots of pieces of information (like Spanish vocabulary), and you now have a very powerful way of learning that results in spending more time with those things you already know and very little time with things you remember easily.

Confidence Reporting

We can still do a little better. Instead of just telling the system whether or not we remember something, we can also report how confidently we were able to do so. Different spaced repetition systems allow you to report a varying number of confidences - sometimes as many as four or five. CleverDeck only has two: right-swipes mean "I knew it", and up-swipes mean "I remembered, but it was tough." We found that having more than two confidence intervals produced more decision fatigue than could be justified by the diminishing benefit of more choices.

Now that you have an understanding of the ideas behind spaced repetition, learn more about how CleverDeck actually implements them.