Should you study one topic at a time or mix them?

October 10, 2026

Say you have five decks for one exam. You can finish one deck before starting the next, or you can shuffle all five together. Researchers call the first way blocking and the second interleaving. Here's what the studies say.

Mixing usually wins on the test

In 2007 Doug Rohrer and Kelli Taylor had college students practice finding the volume of four kinds of shapes. One group practiced each kind in its own block. The other group got the same problems shuffled. On a test a week later, the shuffled group did far better.

Nate Kornell and Robert Bjork found the same thing in 2008 with paintings. People studied paintings by 12 artists, either one artist at a time or all mixed together, and then tried to name the artist of paintings they hadn't seen before. The mixed group did better.

It feels worse while you're doing it

In the Kornell and Bjork study, most people said one artist at a time had worked better for them, even after their own test scores showed the opposite. Blocking feels smooth because each card looks like the one before it. Mixing makes you work out which topic you're in every time, and that effort is part of why it sticks.

So if mixing feels harder, that isn't a sign it's failing.

It depends on what you're learning

In 2019 Matthias Brunmair and Tobias Richter combined the results of 59 studies. Overall, mixing helped by a moderate amount, but the results varied a lot from study to study. The benefit was clearest when the things being learned were easy to confuse with each other, like artists with similar styles or math problems that look alike.

For topics that have little in common, like Spanish verbs and cell biology, there isn't much evidence either way. Mixing them probably doesn't hurt, but it isn't where the gains come from.

Spacing matters more

Mixing decks also spreads out the repeats of each card, and spacing has some of the strongest evidence in learning research. A 2006 review by Nicholas Cepeda and colleagues pulled together hundreds of experiments and found that spreading study out beat doing it all at once.

What MindMaxer does

New cards come in one deck at a time, in order, so you see the basics of a topic before it gets mixed with the others. Reviews pull from every deck you're studying, and the cards you know least come up most. To stay on one topic, study a single deck. To mix, tick several decks or use Study all.

Sources

• Rohrer, D., & Taylor, K. (2007). The shuffling of mathematics problems improves learning. Instructional Science, 35, 481-498.
• Kornell, N., & Bjork, R. A. (2008). Learning concepts and categories. Is spacing the "enemy of induction"? Psychological Science, 19(6), 585-592.
• Brunmair, M., & Richter, T. (2019). Similarity matters. A meta-analysis of interleaved learning and its moderators. Psychological Bulletin, 145(11), 1029-1052.
• Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks. A review and quantitative synthesis. Psychological Bulletin, 132(3), 354-380.