“Conditions that create challenges for the learner and appear to slow the rate of learning often enhance long-term retention and transfer.” —Robert A. Bjork
Interleaving is the practice of mixing different topics, problem types, or skills within a single study session, rather than studying one thing to completion before moving to the next. Its opposite—studying in long, single-topic runs—is called blocked practice. Interleaving is the third of the three pillars of durable learning, alongside active recall and spaced repetition, and like its siblings it is counter-intuitive: it feels worse while you do it and works better when it counts.
