How to Make Flashcards That Actually Stick

Flashcards are one of the few study methods that combine the two techniques with the strongest research behind them: testing yourself and spacing your practice over time. But a bad deck can waste hours. If you've ever flipped through 200 cards, recognized every answer, and still blanked on the exam, the problem was probably how the cards were written.

Here's how to make flashcards that actually stick, whether you use index cards or an app.

Why flashcards work (when they're done right)

Every time you pull an answer out of memory, you make it easier to pull out again. Psychologists call this retrieval practice, and it consistently beats rereading. In one study, students who tested themselves on material remembered far more of it a week later than students who spent the same time rereading (Roediger and Karpicke, 2006).

The second ingredient is spacing. Seeing a card once a day for four days beats seeing it four times in one sitting. One study on flashcards specifically found that spreading the same cards across several sessions led to better learning than cramming them, for most students, even though the students themselves thought cramming worked better (Kornell, 2009).

So a good flashcard does one thing: it makes you retrieve a single piece of information, on a schedule. Everything below follows from that.

Rule 1: One fact per card

The most common mistake is the overloaded card.

Bad:

• Front: Mitochondria
• Back: Double membrane, inner membrane folded into cristae, site of the Krebs cycle and electron transport chain, has its own DNA, produces most of the cell's ATP

You'll read that back, nod, and feel like you knew it. You didn't. You recognized it. Split it up:

• What structure increases the surface area of the inner mitochondrial membrane? Cristae
• Where in the cell does the electron transport chain happen? Inner mitochondrial membrane
• Which organelle besides the nucleus has its own DNA in animal cells? Mitochondria

Five small cards take longer to make than one big one, but each one is something you either know or don't. That's what makes the review honest.

Rule 2: Ask a question, don't write a label

A front that just says "Mitochondria" or "Stamp Act" doesn't tell you what to retrieve. You end up reciting whatever comes to mind and calling it close enough.

Phrase the front as a question with one right answer:

• Instead of "Stamp Act": What did the Stamp Act of 1765 tax?
• Instead of "Operant conditioning": What's the difference between negative reinforcement and punishment?
• Instead of "Metoprolol": What drug class does metoprolol belong to?

If your answer could be a paragraph, the question is too broad.

Rule 3: Use your own words

Copying a textbook definition onto a card is fast, but you end up memorizing a sentence instead of an idea. Rewrite it the way you'd explain it to a classmate. If you can't, that's a sign you don't understand it yet, and you just found what to study.

The exception is anything you need word for word: formulas, legal standards, exact definitions your professor will look for.

Rule 4: Break lists and processes into pieces

Lists are where flashcards go to die. "Name the 12 cranial nerves" as a single card is miserable to review and you'll keep missing the same two.

Instead:

• Make one card per item with a cue: Which cranial nerve controls the muscles of facial expression?
• Or use cloze cards (fill in the blank): The sequence of mitosis is prophase, ___, anaphase, telophase.
• For processes, make a card for each step and one for the order: What happens right after glycolysis when oxygen is present?

Rule 5: Add images where the subject is visual

Anatomy, art history, chemistry structures, maps, histology slides: if you'll be shown a picture on the exam, put the picture on the card. Label one structure at a time and ask "What is the structure marked A?" rather than putting a fully labeled diagram on the back.

Rule 6: Make some cards go both ways

For vocabulary, drug names, terms in a language class, it helps to have both directions: term to definition and definition to term. Exams test both. Most apps can create the reverse card for you.

Paper or app?

Both work. The rules above matter more than the medium.

Paper index cards are good for small decks and for subjects where drawing helps. Writing them out is also a form of studying. The weak spot is scheduling: you have to sort cards into piles yourself. The classic way is the Leitner system: cards you get right move to a box you review less often, cards you miss go back to the box you review every day.

Apps handle the scheduling for you. Anki and Quizlet are the best known (here's an honest comparison of the two). Spaced repetition apps show you each card right before you're likely to forget it, which saves a lot of time on cards you already know.

How many flashcards a day?

For most college classes, 20 to 50 new cards a day plus reviews is plenty, and that usually takes 15 to 30 minutes. The reviews pile up over time, so starting a big deck three days before the exam doesn't work well. Start when the unit starts and add cards after each lecture.

If you're already behind, prioritize. Make cards for the topics most likely to be tested and the ones you keep missing, and use other methods (practice questions, the blurting method) for the rest.

How to review so it counts

• Say or write the answer before you flip. Thinking "yeah, I know this" doesn't count.
• Be strict. If you got it half right, mark it wrong. The card will come back sooner, which is what you want.
• Shuffle. Going through cards in the same order lets you learn the sequence instead of the facts.
• Delete or fix bad cards. If a card keeps confusing you, the card is usually the problem. Split it or rewrite it.

Good cards by subject

Notice the pattern: each better card asks for one specific answer, and you can't get it right by recognizing the topic name.

How to fix a deck that isn't working

If you're putting in the time and still forgetting things on the exam, check for these problems:

• You recognize answers but can't produce them. Your fronts are probably labels. Rewrite them as questions.
• The same cards keep failing. They're probably too big or too similar to other cards. Split them, or add a distinguishing detail to the front.
• Reviews take forever. You might have too many new cards a day, or cards you don't need. Delete anything that won't be tested.
• You know the cards but not the exam questions. Flashcards are good for facts, not for applying them. Add practice questions to your routine.

Making flashcards faster

Writing good cards takes time: easily an hour per lecture if you do it carefully. That's time well spent early in the semester, but during finals it adds up fast.

One option is to generate a first draft from your material and then edit it. The Revizly flashcard maker reads your lecture slides, a PDF or photos of your notes and writes one-fact-per-card flashcards with spaced repetition built in. You still review them, delete the ones you don't need and add the details your professor stressed, but you skip the typing.

Whichever way you make them, the rules stay the same: one fact, a real question, your own words, and a few minutes every day.

Sources

The two ideas behind good flashcards, retrieval practice and spacing, come from decades of research. These are the studies cited above:

• Roediger, H. L., and Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249 to 255. doi:10.1111/j.1467-9280.2006.01693.x
• Kornell, N. (2009). Optimising learning using flashcards: Spacing is more effective than cramming. Applied Cognitive Psychology, 23(9), 1297 to 1317. doi:10.1002/acp.1537