Interleave topics within a session

Mix related topics in one session instead of doing all of one before the next.

Why it works

Switching between topics forces you to repeatedly retrieve and re-select the right approach, which both adds spacing within the session and trains the discrimination skill of knowing which method a problem calls for. Blocking lets you coast on the last answer.

How to do it

1. Shuffle problem types or decks rather than grinding one to completion.
2. Accept that interleaved practice feels harder and slower — that is the mechanism working.
3. Group topics that are easy to confuse, so you practice telling them apart.

Evidence

Interleaving improves long-term retention and the ability to choose the right strategy, especially for related categories, shown across controlled studies — though it feels less effective to learners while they do it. (rct)

For wholly unrelated material the benefit is mainly the added spacing; interleaving shines most when items are confusable.

Common mistake

Blocking one topic until it feels mastered, which produces fast in-session fluency but weaker retention and poor strategy selection later.