Spaced practice or distributed practice is the opposite of massed practice. In spaced practice, the learning is broken up into a number of parts over a period of time. The period is much longer than that in a massed practice.
From scientific research, it has been proved that if humans are made to learn items in a list in parts – first 10 items in a day, next 10 on some other day, and so on - , the learning is more effective than when all items in the list are to be learnt on a single day. This phenomenon is called ‘Spacing Effect’.
Another example of spacing effect is preparations for an exam. Studying daily for an exam scheduled after a month is more effective than intense studying on the night before the exam. This research was first published in 1939 and has since become one of the most important publications with respect to programming.