The idea
Interleaving mixes related problem types so the learner must decide which approach fits. A block of identical exercises can make method selection unnecessary because the page itself reveals the strategy. Mixing creates practice in recognizing the structure of a problem.
Worked example
A learner studies percentages, averages, and opportunity cost. In a mixed set, a headline about theft rates requires a denominator, a time estimate requires an average, and a scheduling choice requires a forgone alternative. The learner must identify the task before calculating or explaining. If she applies a percentage formula to every prompt, the error exposes a classification problem that ten identical percentage exercises might have hidden.
Use it carefully
Randomly shuffling unrelated material is not always useful. Novices may need clear instruction and initial guided practice before comparing methods. Interleaving should preserve enough connection for meaningful discrimination. Review why a method applies, not merely whether the final answer matches. A harder session can feel less fluent without being less valuable, but difficulty alone is not proof of effective practice.
FROM UNDERSTANDING TO ACTION
Put it to work.
Create six short problems from three related topics, mix them, and explain the method choice before answering each.
RETRIEVE. REASON. REMEMBER.
Knowledge check.
Choose one answer for each question, then check your reasoning.
Sources & further reading.
Links support the core concepts or identify the book. Examples, exercises, and critical analysis are original Institute material. Source checks are not an independent expert review of every claim.
- The Learning Scientists: interleaving and selecting strategies ↗
The Learning Scientists: interleaving and selecting strategies; supports the core concept. Scenarios, calculations, and practice questions are original. Source reviewed 2026-10-19.