How to write flashcards that work

Most flashcards fail for the same few reasons. Here are the rules that fix them, with the before and after for each one.

You can have the best schedule in the world and still get nowhere, because the app can only decide when to show you a card. What’s on it is up to you.

Here are the six things that make the difference. None of them take longer than writing a bad card.

1. One card, one fact

This is the big one. If a card has three things on the back, you can’t answer it “right” — you get one part, miss another, and now you don’t know what to press. The schedule gets a muddled answer and gives you a muddled gap.

Before — Front: “Mitochondria” · Back: “Organelle that makes ATP by aerobic respiration, has a double membrane and its own DNA, sometimes called the powerhouse of the cell”

After — Four cards. “What does the mitochondrion make?” · “Which respiration makes ATP in the mitochondrion?” · “How many membranes does a mitochondrion have?” · “Which organelle carries its own DNA?”

Four short cards beat one long one every time. They’re quicker to answer, and each one gets a schedule that fits how well you actually know that bit.

2. Write the question you’ll be asked

A card with just a word on the front tests recognition. A card with a question on the front tests recall — which is what a test asks for.

Before — Front: “Treaty of Versailles”

After — Front: “Which treaty ended the First World War, and in what year?”

3. Say enough that the answer is the only answer

If a card could sensibly have three different answers, you haven’t written a question, you’ve written a topic. You’ll press “Not yet” on it forever and never know why.

Before — Front: “Why did the Roman Empire fall?”

After — Front: “Name the economic reason for the fall of Rome given in our textbook.”

Big open questions are worth thinking about. They’re just not worth putting on a flashcard.

4. Make it go both ways when both ways matter

Knowing that perro means dog does not mean you can produce perro when you want to say dog. Those are two different skills and they need two cards.

This matters most for languages and for anything with a name attached to a definition. It matters less for things you’ll only ever be asked one way round — you don’t need a card that says “1789” on the front.

5. Write it in your own words

Copying a definition straight off a slide is the fastest way to make a card and the slowest way to learn one. You end up memorizing a shape of words instead of an idea, and then the test phrases it differently and you’re stuck.

Rewriting it forces you to check that you actually understood it. Half the value of making cards happens while you’re making them.

6. Cut the card down

Every extra word on the back is a word you have to produce to feel like you got it right. Keep the answer to the shortest thing that would be marked correct.

Before — Back: “The powerhouse of the cell, which is responsible for generating most of the cell’s supply of adenosine triphosphate”

After — Back: “ATP”

A quick test for a card you’re unsure about

Cover the back and read the front out loud. If you can’t tell what kind of answer is wanted — one word? a list? a date? — the front needs work. If you can say the answer but the back has more than that on it, the back needs cutting.

How many cards is too many

A set of 200 cards made in one evening is a set you’ll never finish. Twenty good cards you review honestly will beat it easily.

Make cards as you go through a topic rather than all at once at the end. You’ll write better ones, because you’ll still remember which bits confused you.

Next: how to plan the weeks before a test, or how Machi.study decides when to show you a card.