In a previous article we have discussed the ‘Spacing Effect’ to help you study more effectively and efficiently. Spacing is a powerful study tool and by doing a bit of work little and often, compared to doing it all at once, you are more likely to remember the information. This is because the time in-between your studying allows you to forget and re-learn the information which helps cement it into your long term memory. Spacing is such a useful tool and studies have found that students who use spacing instead of cramming when revising have a 10-30% difference in final test results (1).
So, what’s all this interleaving business and what does it have to do with spacing?
Interleaving is another study technique which is about what you do with your time when revising, compared to spacing is how long you leave between revision sessions.
You may have found yourself in a position where you will dedicate a day to revise one topic, such as biology, and another day to revise chemistry. This is known as ‘blocking’ – where you ‘block’ a day to commit to one particular topic. It’s quite easy when you are planning your revision timetable to do this and it is something which I’m sure we have all done in the past.
Interleaving is the opposite of this. Instead of dedicating one day to one subject, you mix up the subjects and do a bit of both subjects each day.
A study examining the performance of math students who revising using blocking compared to those who used interleaving showed that the students who had used interleaving performed better on the examination if the examination was more than one day away (2).
By mixing up your revision material you can help make links between the different subjects you are studying. Considering the overlap between A-level subjects, such as biology and chemistry, biology and psychology, and chemistry and maths, this can be a beneficial way to tackle your revision. By making links between subjects, it will also help you discriminate between the different types of problems presented to you and this can aid you finding a solution for them.
There are a few further theories to explain the effect of interleaving. One suggests that interleaving strengthens memory associations compared to blocking, which temporarily holds information in your short term memory. This would perhaps suggest that in the study comparing students who used blocking to interleaving, those who had used the blocking revision method performed better in the examination if the test was the next day. By interleaving, your brain is continually changing focus and attempting to find different responses to bring them into your short-term memory.
So, in conclusion, it’s best to think about your revision like your eating habits. Little and often, and mix it up everyday! Variety is, after all, the spice of life.