Interleave your review, not just your first pass
Review old topics mixed in with new ones instead of reviewing each unit in isolation.
Key takeaways
- What it is: Review old topics mixed in with new ones instead of reviewing each unit in isolation.
- Why it works: Reviewing one unit at a time recreates blocking at the review stage, letting you coast on still-familiar material. Folding old topics back into the current mix forces retrieval of things you have started to forget, which is precisely when retrieval strengthens memory most.
- Evidence: Backed by randomized trials / meta-analyses.
- Avoid: Treating review as a separate, single-topic block done right before a test, which feels reassuring but skips the harder, more useful mixed retrieval.
Why it works
Reviewing one unit at a time recreates blocking at the review stage, letting you coast on still-familiar material. Folding old topics back into the current mix forces retrieval of things you have started to forget, which is precisely when retrieval strengthens memory most.
How to do it
- 1Each session, add a few problems from earlier units into the current mix.
- 2Prioritize the older topics you can least reliably recall.
- 3Keep the share of review high enough that nothing fully fades.
What the evidence says
RCT / meta-analysisMixing prior material into current practice combines interleaving and retrieval practice, both well-supported effects: retrieving partly-forgotten information produces stronger long-term retention than re-reading it while still fresh.
Honest caveat: This is an application of established interleaving and retrieval findings to the review stage; the staged-review format itself is less directly tested than the underlying effects.
Common mistake
Treating review as a separate, single-topic block done right before a test, which feels reassuring but skips the harder, more useful mixed retrieval.
IX Coach quietly threads older skills back into new sessions, so review happens as interleaved retrieval rather than a last-minute single-topic cram.
Practice this with IX Coach →