Definition
Interleaving is the practice of mixing different but related topics or problem types within a single study session, instead of blocking practice on one type at a time.
Why it matters
Interleaving makes practice harder in the moment, but builds the discrimination and flexibility needed to pick the right method when facing new problems.
Scientific basis
Studies of interleaving in mathematics, music, and categorisation show it produces better long-term retention and transfer, even when blocked practice feels easier.
How to apply it
- Mix problem types within a study set instead of finishing one type before starting another.
- Alternate between related but distinct skills, such as different brush strokes or different algorithms.
- Return to earlier topics across sessions to keep the mix active.
Common mistakes
- Believing blocking is more efficient because each item feels clearer.
- Treating interleaving as random scrambling rather than as deliberate mixing of related material.
- Giving up on interleaving because it feels harder than blocking.
Examples
- Practising a mix of geometric volume problems produces better transfer than practising one shape at a time.
- Mixing bird species during identification practice improves categorisation in the field.
Related concepts
- Varied Practice (complements)
Interleaving is a specific kind of varied practice; together they build flexible skill. - Desirable Difficulties (is an instance of)
Interleaving is a desirable difficulty.
Where it shows up
Domains: math-and-science, student-learning, creative-skills. Appears in the Practice & Spacing cluster alongside 3 other concepts.
Source books
- Make It Stick: Brown, Roediger & McDaniel
Articles that use this concept (3)
- Interleaving, Explained Like a Friend: interleaving practice
- Build an Interleaved Practice Week: interleaved study schedule
- Interleaving vs. Blocking: A Practical Comparison: interleaving vs blocking