How does interleaving improve long-term retention?

Short Answer

Interleaving mixes related topics or problem types during practice instead of blocking one topic at a time. It improves retention by training you to recognize which strategy fits and when.

Why This Matters

Because switching forces comparison and discrimination, you learn the cues that separate similar ideas rather than relying on repetition. It often feels harder in the moment, but that “desirable difficulty” leads to stronger, more flexible memories.

Where This Changes

Interleave after you have basic competence; beginners may need some blocked practice first. Don’t interleave unrelated topics at random—mix things that are easily confused so discrimination improves.