The amount of time we spend revising is always a controversial issue – some people prefer to downplay how much time they’ve spent reviewing, whereas others are keen to tell you how much revision they’ve done. The fact is we’re all different in how much time we spend studying, but if an active recall is a useful technique, the next question I want to address is how we should be using it to enhance our performance. This is where spaced repetition comes in.
Spaced Repetition vs. Cramming – The Theory and Evidence
As the name suggests, spaced repetition involves spacing your revision and reviewing topics, ideally by the active recall, at specific intervals over time.
It can be explained by the ‘forgetting curve’ – an idea that has been around in the psychology literature for over one hundred years. The forgetting curve is the idea that over time we forget things at an exponential rate.
The way we can take advantage of the forgetting curve is by breaking the cycle and reviewing material at spaced intervals. This might be obvious to you, but its importance cannot be overstated. The more that we practice and the more spaced this repetition becomes, the more likely we are to encode this information into our long-term memory.
In essence, the idea behind spaced repetition is that you allow your brain to forget some of the information to ensure that the active recall process is mentally taxing. The psychology literature suggests that the harder your mind works to retrieve information, the more likely it is for that information to be encoded.
By spacing our repetition by a day, three days, then a week, we allow ourselves to forget some of the information so that when we revise the topic – through active recall – it takes active brainpower. Re-reading, on the other hand, has low utility because it is a passive exercise – just testing yourself once has been shown to be more effective than re-reading the same passage four times.
What’s even more astounding is that evidence suggests that, even within the same study session, spaced repetition can be a more efficient technique in terms of retaining information. A 2011 study involving four groups of students who were tasked with trying to learn words in Swahili found that recalling information even within the same session had dramatic benefits. In the study, one group only studied the terms once, and this didn’t produce impressive results. The second group saw each word once and then had to recall a word once before being tested, and as you can see from the graph, just through recalling a word once, your performance increases. The third group had to recall the same words multiple times, which produced similar results to Group 2.
However, most interestingly, the final group saw each word, recalled it, then had a gap of a few more words before recalling the first word again. In effect, this final group spaced their recall, and as the graph illustrates, the results are astonishing.
The students were doing the same work – the only difference being that their recall was spaced out compared to groups 2 and 3. This study not only emphasizes the power of active recall but also provides firm evidence of the power of spaced repetition and how we only need to restructure our revision slightly to obtain a substantial improvement in our ability to remember and recall information.
This active recall-spaced repetition combination can easily be adapted into our studying. For instance, let’s say you studied Topic 1 and Topic 2 one morning and planned to move to Topic 3 and Topic 4 in the afternoon. The results from this study demonstrates that you should go back to Topic 1 and write down – through active recall – what you can remember before moving onto Topic 3. You would then repeat this for Topic 2 after having studied Topic 3 and so forth.
In essence, spaced repetition over days and weeks, as well as reviewing the content on the same day, can both be extremely helpful for improving exam performance.
Applying Spaced Repetition
In practical terms, using active recall and spaced repetition could be as simple as taking a pen and paper at the end of the day and answering your active recall questions, or constructing a spider diagram of what you’ve learned. In essence, all with your book closed!
But I know that different techniques work better for some people compared to others. The following strategies are the ones that worked effectively for me – if you’re struggling with your studying, then perhaps give these a try.