How to improve your memory – Meta skills part 5

The faster you can master new knowledge, the better you’ll be able to do your job and have more impact. But what’s the best way of learning? The most promising method is spaced repetition – flashcards done well.

Learn more effectively using a spaced repetition system

Imagine that one day you learned that the capital of Ethiopia was Addis Ababa. If you were tested the next day, you’d have a high chance of remembering this. If instead you were tested the next week, you’d have a lower chance of remembering it. This is common sense, and can be represented by a curve that shows your forgetting over time. If you review the item some days later, you then get a new, more gradual forgetting curve:

You will forget slower this time, because this is your second review. This means that if you want to learn efficiently, you should learn something, then review it at intervals later, but that the intervals should get wider and wider:

As well as this optimal pattern of review, psychologists have shown1 that active recall (i.e. practice testing) is better than passive recall – i.e. it is better to review by asking “What is the capital of Ethiopia” and forcing yourself to answer than to review by simply reading “The capital of Ethiopia is Addis Ababa”.

Spaced repetition software uses these principles. You make question-and-answer flashcards and when you’ve answered a question the software works out the best time to test you again. So all the scheduling is taken care of for you.

But can you use this technique to learn complex information rather than simple facts such as world capitals? According to people who have tried it, yes, it’s possible. You just need to make sure you break down the information in the right way. This list of 20 rules for writing flashcards will help you break down complex information. And for an example of how to learn complex information using flashcards have a look at this detailed guide by someone who has used spaced repetition to study computer programming.

What are the benefits?

If you can accelerate your learning then you’ll be able to learn more information useful for your job. You also get compound benefits from knowledge. The more you know, the more easily you can learn related topics and make links between different areas of knowledge to come up with novel solutions. There are lots of useful things you could learn: if you’re a student you could study your subject more efficiently. If your job involves a lot of networking you could use spaced repetition to learn names and information about people that you need to remember. Every time you come across something useful you didn’t know, you can make a new flashcard in seconds.

What are the potential costs?

Daily spaced repetition costs vary dependent on how many cards you review each day. I just reviewed 36 cards in 6 minutes, for example. However, it’s a very efficient way of learning things. The spacing means that you can maintain a deck of thousands of cards and still only take 15 minutes a day to review (depending on how fast you add cards). Given that the software finds a close-to-optimum schedule of reviewing, any other schedule of review would either take more time or would cause you to forget more.

Gwern estimates that at the very most, you’d spend 5 minutes over the course of your lifetime on each card. “if, over your lifetime, you will spend more than 5 minutes looking something up or will lose more than 5 minutes as a result of not knowing something, then it’s worthwhile to memorize it with spaced repetition. 5 minutes is the line that divides trivia from useful data.”

How strong is the evidence?

Some psychologists recently published a review of the best learning methods. They found that practice testing and distributed practice (where you space practice sessions over time rather than cramming all at once) came out top. Both of these methods are used in spaced repetition. You can see a full review of the evidence for spaced repetition here.

Our recommendation

  • Choose something to learn – start with something that’s fairly easy to break down into small facts, but make sure that you actually care about learning it, otherwise you won’t want to do the reviews.
  • Read 20 rules for writing effective flashcards


  • Anki – free and easy to use.
  • Memrise – web-based system with a game-like setup and lots of cards for language learning.

The full series:

  1. Introduction
  2. Commitment Devices
  3. Task management
  4. Prioritisation
  5. Spaced repetition


  1. Dunlosky, John et al. “Improving Students’ Learning With Effective Learning Techniques Promising Directions From Cognitive and Educational Psychology.” Psychological Science in the Public Interest 14.1 (2013): 4-58.