What Is Interleaving? The Study Technique That Beats Blocked Practice

Short answer. Interleaving is the study technique of mixing different topics or problem types within a single study session, rather than practicing one topic to mastery before moving to the next ("blocked practice").

Example

Math practice:

Interleaved practice usually feels harder — and that's the point.

Why it works

When topics are mixed, you have to:

Blocked practice lets you cruise on autopilot once you've identified the pattern; interleaved practice forces the discrimination step that real exams (and real life) require.

The research

Rohrer & Taylor (2007) showed math students who interleaved scored ~25-30% higher on delayed tests than students who used blocked practice with the same total time. The blocked students performed better in the moment; the interleaved students performed better when it mattered (the test).

This is one of Bjork's "desirable difficulties" — practice that feels harder produces better learning.

When to use interleaving

When to use blocked practice:

Interleaving + spaced repetition

These work well together. A spaced repetition system that surfaces cards from multiple subjects in one session is naturally interleaved.

Related reading

Generate quizzes across multiple topics and practice interleaved.