The Study Technique That Feels Wrong But Actually Works

If you asked most students how to study for three different math topics, they’d say: master topic one completely, then move to topic two, then topic three. This approach — called “blocked practice” — feels organized and satisfying. It’s also, according to a large body of research, one of the least effective ways to build lasting understanding. The better approach, called interleaving, feels messy, uncomfortable, and slower — which is exactly why most students avoid it, even though it works better.

What Interleaving Actually Means

Interleaving means mixing different but related topics or problem types together during a single study session, instead of practicing one thing repeatedly until it feels mastered before moving on. Instead of solving twenty of the same type of algebra problem in a row, you’d solve a mix of five different problem types, shuffled together, so you never quite know what’s coming next.

At first, this feels much harder. Your performance during the actual study session often looks worse than with blocked practice — more mistakes, slower solving, more confusion about which method to apply. This is precisely why students instinctively avoid it: it doesn’t feel like it’s working.

Why It Works Better Despite Feeling Worse

Researchers distinguish between performance — how well you do during practice — and learning — how well you retain and apply the skill later, especially in new situations like an exam. Blocked practice inflates performance during study sessions but doesn’t build the skill that actually matters most: knowing which method to use when the problem type isn’t labeled for you.

Think about it from the exam’s perspective. A real exam almost never groups all the same type of question together with a helpful heading. It mixes problem types, forcing you to first identify what kind of problem you’re looking at before you can even begin solving it. Blocked practice never trains this identification skill — you always already know what method to use because you’ve been drilling the same one for the last ten minutes. Interleaving forces you to practice the exact skill an exam demands: recognizing which tool fits which problem, under uncertainty.

A Concrete Example

Imagine a student studying three types of geometry problems — area, volume, and surface area.

Blocked approach: Solve ten area problems in a row, then ten volume problems, then ten surface area problems.

Interleaved approach: Solve problems in a shuffled order — area, surface area, volume, area, volume, surface area — so the student never knows in advance which type is coming next.

Studies comparing these two approaches on delayed tests (days or weeks later, mimicking real exam conditions) consistently find that students who used interleaved practice score noticeably higher than those who used blocked practice, even though the interleaved group felt more confused and made more mistakes during the original study session.

How to Apply Interleaving to Your Own Studying

• Mix problem types within a single session, rather than dedicating an entire session to one type. If you’re revising three related topics, don’t finish one entirely before starting the next — rotate between them.
• Mix subjects across a study day, not just topics within a subject. Instead of three hours of only physics, try alternating shorter blocks of physics, chemistry, and math.
• Use practice sets that don’t tell you the topic in advance. A worksheet labeled “Chapter 5: Quadratic Equations” defeats the purpose, because you already know the method before reading the question. Shuffle practice questions from multiple chapters together, or use a mixed past exam paper.
• Expect to feel less confident during practice. This discomfort is a normal, expected part of the process — not a sign that it isn’t working. The benefit shows up later, at the exam, not immediately.

A Balanced Approach

Interleaving isn’t meant to completely replace focused, repetitive practice — especially when you’re first learning a brand-new concept and need some initial repetition just to grasp the basic mechanics. A reasonable approach is to use a small amount of blocked practice to get comfortable with a new topic initially, then shift to interleaved practice once you have a basic handle on multiple related topics, mixing them together for the deeper, longer-term learning phase.

The Takeaway

Interleaving is uncomfortable precisely because it works. It trades the false confidence of blocked practice for the harder, more honest skill of recognizing and adapting — which is exactly what an exam, and frankly most real-world problems, actually demand. If your practice sessions never feel a little confusing, you might be optimizing for a comfortable study session instead of a strong exam.