Interleaving: Mix Similar Problems to Learn the Difference

The standard approach to practice is blocking: do ten of the same type of problem, then move to the next type. It feels productive because you get into a rhythm and the answers come easily. But that ease is misleading — you're not learning to identify which approach to use, because the context already tells you. Interleaving means mixing different types of problems together, forcing your brain to first figure out what kind of problem it's looking at before solving it.

This feels harder and slower, and your accuracy drops at first. That's the point. The struggle of distinguishing between similar problems is exactly the skill you need in real life, where nobody labels the problems for you. Research consistently shows that interleaved practice produces better long-term retention and transfer, even though it feels less pleasant in the moment. Choose the method that works, not the one that feels smooth.