Interleaving is a powerful learning technique where you mix related but distinct topics or problem types during a single study session, rather than focusing on one topic at a time (known as "blocked practice"). Research shows interleaving improves long-term retention and enhances your ability to discriminate between different concepts and apply the right strategies to different problems.
Why Interleaving Works
Interleaving enhances learning by:
- Creating connections between related concepts
- Forcing your brain to actively retrieve information
- Improving your ability to discriminate between similar concepts
- Preventing the illusion of mastery that comes from blocked practice
- Simulating real-world application where problems aren't neatly categorized
Step-by-Step Guide to Creating an Interleaved Study Schedule
Step 1: Identify Related Topics to Interleave
Interleaving works best with related but distinct topics. For example:
- Different math concepts (algebra, geometry, calculus)
- Different grammar rules or language structures
- Various historical periods with similar themes
- Different scientific principles that relate to each other
Avoid interleaving completely unrelated subjects (like Spanish vocabulary and calculus).
Step 2: Break Down Your Material into Manageable Chunks
Divide each subject or topic into smaller components that can be studied in 15-30 minute segments.
- Limits
- Derivatives - basic rules
- Derivatives - chain rule
- Derivatives - product/quotient rules
- Integration - basic techniques
- Integration - substitution method
Step 3: Create Your Interleaved Schedule
Develop a schedule that alternates between topics within a single study session.
| Time | Topic | Activity |
|---|---|---|
| 25 minutes | Derivatives - chain rule | Practice problems |
| 5 minutes | Break | Short rest |
| 25 minutes | Integration - basic techniques | Practice problems |
| 5 minutes | Break | Short rest |
| 25 minutes | Limits | Practice problems |
| 5 minutes | Break | Short rest |
| 25 minutes | Derivatives - product rule | Practice problems |
| 5 minutes | Review | Summarize connections between topics |
Step 4: Incorporate Spaced Repetition
Combine interleaving with spaced repetition by revisiting topics at increasing intervals over time.
- Monday: Topics A, B, C
- Wednesday: Topics D, E, A (revisit)
- Friday: Topics B (revisit), F, C (revisit)
- Next Monday: Topics D (revisit), E (revisit), G
Step 5: Include Problem Variation
For each topic, practice different types of problems that require different approaches.
- One-sample t-tests
- Two-sample t-tests
- Paired t-tests
- Chi-square tests
This forces you to identify the correct test for each situation rather than applying the same formula repeatedly.
Step 6: Add Regular Retrieval Practice
End each study session with a brief self-quiz that covers all the interleaved topics.
Start subsequent sessions with a quick review of previously studied material.
Sample Interleaved Study Schedules
For Language Learning
- 15 min: Vocabulary practice (new words)
- 15 min: Grammar rule #1
- 5 min: Break
- 15 min: Reading comprehension
- 15 min: Grammar rule #2
- 5 min: Break
- 15 min: Speaking practice that incorporates vocabulary and both grammar rules
- 5 min: Review and identify connections
For Multiple Subjects
| Day | Morning Session (2 hours) | Afternoon Session (2 hours) |
|---|---|---|
| Monday |
Biology: Cell structure (30 min) Chemistry: Atomic structure (30 min) Biology: Cell division (30 min) Chemistry: Chemical bonding (30 min) |
Psychology: Memory (30 min) History: Industrial Revolution (30 min) Psychology: Learning theories (30 min) History: World War I (30 min) |
| Tuesday |
Chemistry: Chemical reactions (30 min) Biology: Genetics (30 min) Chemistry: Stoichiometry (30 min) Biology: Evolution (30 min) |
History: Great Depression (30 min) Psychology: Development theories (30 min) History: World War II (30 min) Psychology: Personality theories (30 min) |
Practical Tips for Effective Interleaving
When learning a completely new concept, start with some blocked practice to gain basic familiarity before moving to interleaving.
Interleaving feels more difficult than blocked practice, and you might feel like you're learning more slowly. This is normal! The increased difficulty actually leads to better long-term learning.
Since you're switching between topics, maintain clear, organized notes for each subject to avoid confusion.
Actively note how concepts are similar and different as you switch between them.
Study different topics in slightly different locations or positions to create additional memory cues.
Tracking Your Progress
Keep a learning journal that tracks:
- Which topics you interleaved
- How difficult each session felt (1-10 scale)
- What connections you discovered between topics
- Questions that arose during studying
Periodically test yourself on all topics to measure your retention and understanding.
Conclusion
Creating an effective interleaved study schedule requires more planning than traditional blocked studying, but the benefits for long-term retention and transfer of knowledge are substantial. Remember that it should feel challenging—that's a sign the technique is working! Start with related subjects, create a structured schedule with deliberate topic switching, and combine with spaced repetition for maximum effectiveness.