ABSTRACT
The benefit of spaced practice to learning is arguably one of the strongest contributions that cognitive psychology has made to education. The effect is simple: repetitions spaced out over time will lead to greater retention of information in the long run than the same number of repetitions close together in time. Interleaving is another planning technique that can increase learning efficiency. Spaced practice has been investigated in many different subjects and learning contexts, from simple vocabulary learning, fact learning, and learning from text passages, to problem solving, motor skills and learning to play a musical instrument. Interleaving occurs when different ideas or problem types are tackled in a sequence, as opposed to the more common method of attempting multiple versions of the same problem in a given study session. The cognitive processes behind the effectiveness of interleaving are still under debate.
