Interspersal
Mixing known, easy tasks in with new or difficult ones to maintain motivation and reduce escape behaviour.
Interspersal involves embedding mastered or easy tasks throughout a block of difficult work. Instead of presenting ten hard problems in a row, you alternate - hard, easy, hard, easy - so the learner regularly contacts success and reinforcement throughout the session.
You use this when a learner's escape behaviour is triggered by prolonged exposure to difficult material. A solid run of failures or high-effort responding depletes motivation fast. Interspersing easier items resets the emotional tone of the session without reducing the overall demand load.
Interspersal is different from shortened task length. You're not doing less work - you're changing the ratio of hard to easy within the same session. Done well, the learner accesses more reinforcement, the session stays productive, and you gradually shift the ratio toward more difficult items over time.
The most common mistake is choosing 'easy' tasks that aren't actually fluent for the learner. If the easy tasks still require effort, they don't serve their function. They need to be quick wins - things the learner can do automatically.
Implementation
- Identify the target difficult tasks and a pool of mastered, fluent tasks.
- Arrange the session to alternate between difficult and easy items.
- Provide reinforcement for completion of each item, not just the difficult ones.
- Monitor the ratio over time and gradually shift toward more difficult items as tolerance builds.
- Track celeration on the difficult targets to ensure progress isn't stalling.
Common Mistakes
- Using 'easy' tasks the learner hasn't fully mastered.
- Interspersing so many easy tasks that the difficult targets get insufficient practice.
- Removing the easy tasks too quickly once the learner shows initial improvement.