Interleaving
Interleaving means mixing different problems or topics within one study session rather than practising them in separate blocks. It feels harder than blocked practice, but it produces better long-term retention and a stronger ability to tell similar things apart.
Blocked practice — doing twenty of the same kind of card in a row — feels smooth because you settle into a pattern. But that smoothness is misleading: you stop having to figure out which approach a card needs, because they are all the same.
Interleaving forces your brain to repeatedly identify what kind of problem it is facing and retrieve the right response, which is exactly the skill you need when the material comes up for real. Studies across maths, categories, and language learning consistently show interleaved practice beats blocked practice for retention and transfer — even when learners feel less confident during the session.
The trade-off is that interleaving feels worse while you do it. That subjective difficulty is a feature, not a bug — it is the same desirable difficulty that makes active recall and spacing work.
How EverFlip does this
EverFlip interleaves automatically. A study session blends due reviews with new cards rather than blocking them, and within a session your cards are shuffled — so you are always discriminating, never autopiloting.