Desirable Difficulties

Desirable difficulties is a concept introduced by psychologist Robert Bjork, describing learning conditions that make initial acquisition of material feel slower or more effortful but that produce stronger, more durable and more transferable long-term learning than conditions that feel easier in the moment. Examples Bjork identified include spacing practice out over time rather than massing it, interleaving different topics or problem types rather than practicing one at a time in a block, and testing oneself on material rather than simply rereading it, all of which slow immediate performance while improving retention measured later. The concept is important in education precisely because it runs against learners' and teachers' intuitions, since the conditions that feel most productive during a single study session are often not the ones that produce the best long-term learning.