Have you ever studied for an exam all day and all night long and having passed with flying colours struggled to remember what the course was about a couple of months later? If the answer is ‘yes’ then you know what massed repetition is. But what is spaced repetition and why is it associated with remembering things you learn better?
Recent advances in understanding of the neurobiology have revealed that learning is not an event, but rather a process that unfolds over time. In this view it is not surprising that spaced repetition as a learning technique which involves repeating material over time enhances its retention. 
As opposed to massed repetition, spaced repetition is more effective for retention of learnt material due to the following [based on 2]:
- encoding variability;
- proficient processing;
- learning-strategy adaptation;
- sleep as a facilitator of memory.
For better retention there should be different contexts in which you learn i.e. encode the same pieces of information. So each time you learn words and phrases, you create a different context if these learning instances do not occur shortly one after another but are spaced in time.
When you space learning instances in time the new vocabulary learnt is processed in between the instances of learning which again facilitates its better retention.
It is more difficult to recall words and phrases you learnt some time ago so you are more likely to use more effective strategies to remember them.
Sleep as a Facilitator of Memory
This cause of effectiveness of spaced repetition might be connected with proficient processing, where in addition once you leave a gap between your learning instances of not less than 24 hours, retention improves. In English there is a phrase ‘to sleep on something’ which reflects it in a way that you need to give your brain a chance to process new data for better decision making which in its turn is not possible without proper encoding, i.e. learning this new data.
Effective and Efficient
Laboratory studies have also demonstrated the long-term memory benefits of studying material in multiple distributed sessions as opposed to one massed session, given an identical amount of overall study time. 
In other words, spaced repetition is not only more effective when you want to retain words and phrases in your long term memory but it is also a more efficient way to learn vocabulary as it saves your time and effort. For example, if you practise the words and phrases you are learning today, tomorrow and the day after, you will remember them better than if you spent the same time practising them on the same day.
Studies show that expanding time intervals are either the same or more effective for memory retention than fixed ones. Therefore it can be even more effective (and efficient!) if you practise the vocabulary you are learning today a couple of days later and then again in 4 days.
Other studies focusing specifically on retaining of foreign language vocabulary showed benefits of repetitions delayed longer, 56 days delayed repetitions being 34% more effective than 14 days ones [2, p. 38].
Very often though we attempt to learn the words and phrases we need to learn in one go just because it’s simpler to do it at once rather than to remember to practise them later as well. As a result we cannot even recognise them a couple of months down the line never mind using them ourselves.
Effective, Efficient and Automated
The good news is vocBlock’s Memoriser helps you organise your vocabulary study for you using spaced repetition to make learning more effective and efficient. Memoriser reminds you to practise the vocabulary you are learning in expanding intervals, i. e. in a week, 2 weeks, 1 month, 2 months and 4 months to ensure better retention (you can always fine tune the number and timing of the repetitions to suit your needs). And it is automated, so all you need to do is follow reminder emails you get in your inbox.
So, you probably managed once to cram all of your studying of World History in a couple of days before the exam (and got nightmares of Vikings under Napoleon’s command invading your humble abode as a result) but using messed massed repetition for studying a foreign language might not be the best idea especially when you have vocBlock’s Memoriser to help you organise your study more effectively and efficiently with no extra effort on your part.
- Spaced Repetition http://www.gwern.net/Spaced%20repetition
- Spacing Learning Events Over Time: What the Research Says, Will Thalheimer, PhD, http://www.phase-6.de/system/galleries/download/lernsoftware/Spacing_Learning_Over_Time__March2009v1_.pdf
- Using Spacing to Enhance Diverse Forms of Learning: Review of Recent Research and Implications for Instruction, Shana K. Carpenter & Nicholas J. Cepeda & Doug Rohrer & Sean H. K. Kang & Harold Pashler, http://laplab.ucsd.edu/articles/Carpenter_etal_EPR2012.pdf
Originally published at blog.vocblocks.com on January 13, 2017.