Optimum Interleaving

Complete the interactive activities in the Seneca app to work towards your CPD certificate.

What is the optimum spacing for learning?

A few scientific papers have tried to discover what is the optimum interval between study sessions.

Karpicke and Bauernschimidt, in 2011, investigated the benefits of expanding, contracting or constant spacing intervals between study sessions.
Their results showed that, in general, spaced sessions increased performance by 200% when compared to massed practice.
However, there was no significant difference between the types of spacing.
- That is, it seems like spaced practice is powerful regardless of how it is done.

Important to notice, however, that that study was done with university students and the stimuli were lists of words. It is unclear what the effects would be when working with teenagers studying for their A Levels.

A few scientific papers have tried to discover what is the optimum interval between study sessions.

Pashler, Zarow and Triplett, in 2003, conducted a study about how spacing affects mistakes students make.
It was already known that spaced practice works better than massed practice.
- However, the authors wanted to know if this was influenced by students initial performance.
- That is, should the interval between sessions be reduced for students that made significant mistakes in their first study session?

To test that, participants learned associated pairs of words followed by two no-stake quizzes with immediate feedback.
Then, they were tested on their performance at the end of the day, a day later and a week later.
Spacing was manipulated by changing the lag between the two no-stake quizzes.

Interestingly, the results showed that the longer the lag between the two no-stake quizzes, the worse the memory in the test at the end of the day. However, the better was performance a day and a week later.
- This means that being tested right after you learn something may help. But spacing out study sessions helps with longer retention of that information.
The results showed that performance a week later increased from 20% to 30% with a longer spacing.

Another interesting finding was that this pattern did not differ between items that participants answered incorrectly or correctly during the first no-stake quiz.
- That is, a longer spacing interval seems to improve long-term memory even if students make an initial mistake.
- In other words, giving students a follow-up quiz because they performed poorly the first time does not increase their long-term performance.