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TIL: Chunking and Interleaving Are Two Study Techniques That Actually Work

Mar 14, 2026

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Most people do the same thing when trying to learn something:

  • cram a lot
  • repeat the same type of problem again and again
  • hope it sticks

Two techniques work better than that in a lot of cases: chunking and interleaving.

They are simple, practical, and useful far beyond school.

Chunking

Chunking means grouping small pieces of information into a few meaningful units.

Instead of remembering:

buy milk eggs bread bananas coffee

you remember:

  • breakfast
  • fruit
  • coffee

Same information. Less mental load.

This works because working memory is limited. George Miller's classic 1956 paper made chunking famous, and later work by Nelson Cowan argued the true limit is probably even smaller than people assume, often closer to about 4 chunks than 7 loose items. The practical point is clear: your brain handles grouped meaning better than random fragments.

Examples:

  • Remembering a phone number as 9841-234-567 instead of 10 separate digits
  • Turning a presentation into 3 main ideas instead of 15 bullets
  • Learning a recipe as prep -> cook -> finish instead of memorizing every step separately
  • Grouping keyboard shortcuts by app or purpose instead of learning them one by one

Chunking is not just for memorizing facts. It helps any time you want to reduce chaos.

Interleaving

Interleaving means mixing related topics or problem types instead of practicing one kind in a big block.

Blocked practice looks like this:

  • 20 algebra questions
  • then 20 geometry questions
  • then 20 probability questions

Interleaved practice looks like this:

  • algebra
  • geometry
  • probability
  • algebra
  • probability
  • geometry

Why does this help? Because learning is not just about doing the task. It is also about recognizing which kind of task this is and choosing the right approach.

That is where interleaving helps. It trains selection, not just repetition.

Rohrer and Taylor found that mixed practice improved later test performance even though it felt harder during practice. A later systematic review by Firth, Rivers, and Boyle found interleaving benefits for both memory and transfer, especially when learners need to tell similar categories apart.

Examples:

  • If you are learning to code, mix debugging, reading code, and writing small functions
  • If you are learning a language, mix listening, speaking, vocabulary, and sentence building
  • If you are preparing for interviews, mix system design, DSA, and behavioral questions
  • If you are learning guitar, mix chords, rhythm, transitions, and a real song

Interleaving usually feels worse while doing it.

That is normal.

Harder practice often creates better long-term learning than smooth practice.

The Simple Rule

Use chunking when information feels too scattered.

Use interleaving when practice feels too repetitive.

One reduces overload. The other improves discrimination.

Both make learning more durable.

References

  • George A. Miller, The Magical Number Seven, Plus or Minus Two (1956): PubMed
  • Nelson Cowan, The Magical Number 4 in Short-Term Memory (2001): PubMed
  • Doug Rohrer and Kelli Taylor, The Shuffling of Mathematics Problems Improves Learning (2007): USF archive
  • Kelli Taylor and Doug Rohrer, The Effect of Interleaving Practice (2010): USF archive
  • Jonathan Firth, Ian Rivers, and James Boyle, A Systematic Review of Interleaving as a Concept Learning Strategy (2021): Strathprints
Gopal Khadka