Practice classifying before solving

Explicitly ask "what kind of problem is this?" before reaching for a method.

Why it works

Because interleaving’s payoff is learning to select the right approach, you can target that skill directly: forcing a classification step trains the discrimination that blocked practice never exercises. Naming the type out loud also recruits retrieval and self-explanation, both of which deepen encoding.

How to do it

1. For each mixed problem, first state its type and why before solving.
2. If you misclassify, note the cue that misled you for next time.
3. Occasionally do a "classify only" pass where you sort problems without solving them.

Evidence

Research on inductive and category learning shows that interleaving improves learners’ ability to categorize new instances, indicating the gain is in selection/discrimination rather than in executing any single procedure. (rct)

Strong evidence for the discrimination benefit; the specific "classify-out-loud" drill is a sensible operationalization rather than a separately validated protocol.

Common mistake

Jumping straight to the procedure you used last time because it is fresh, which skips the very decision interleaving is meant to train.