This article was written for SecEd magazine and first published in November 2017. You can read the original version on the SecEd website here.
You can access the full archive of my columns for SecEd here.
This is part eight of a 10-part series. Catch up with the series so far.
The process of learning is the interaction between our sensory memory and our long-term memory and takes place in the working memory. In order to ensure our pupils learn, therefore, we need to stimulate their sensory memory, gain the attention of – and help them cheat – their working memory, and improve the strength with which information is stored in, and the ease and efficiency with which it can later be retrieved from, their long-term memory. In order to do this, we need to follow these three steps…
First, we need to create a positive learning environment. Second, we need to make pupils think hard but efficiently. And third, we need to plan for deliberate practice.
In Part Seven we said that, once new information had been encoded into long-term memory, we had to help pupils reduce the likelihood of forgetting it, and increase its storage strength so that pupils can access the information at a later stage. We also need to improve the retrieval strength of the information held in long-term memory so that pupils can recall it with ease and efficiency as and when needed.
In short, we need to help pupils practice what we’ve taught them and the secret to doing this well is ensuring that each time a pupil revisits prior learning the task must be as hard as it was the first time they learnt it. This is called deliberate practice.
As well as deliberate practice, however, we can help improve the storage and retrieval strength of the information in pupils’ long-term memories by getting them to engage in spaced – or distributed – practice.
Spaced practice is a straightforward and easy-to-use technique. Consider the following examples.
A year 7 pupil studies for a spelling test. Using a worksheet to guide her practice, she might take one of two approaches. She could practise spelling the words by writing each one several times directly below the word printed on the sheet. After practising one word repeatedly, she would move on to the next one and practise writing that word several times below it. This kind of practice is called massed practice, or cramming, because the pupil practises each word multiple times together, before moving to the next one.
An alternative strategy for the pupil would be to practise writing each word only once, and after transcribing the final word, going back and writing each one again, and so forth, until the practice is complete. This kind of practice is called spaced or distributed practice, because practice with any one word is distributed across time (and the time between practising any one word is filled with another activity – in this case, writing other words).
In this example, the pupil either masses or distributes her practice during a single session.
Now, imagine a year 8 pupil trying to learn some basic concepts for an upcoming test. He might read over his notes diligently, in a single session the night before the exam, until he thinks he is ready for the test – a study tactic called cramming, which practically all pupils use.
Or, as an alternative, he might study his notes and texts during a shorter session several evenings before the exam and then study them again the evening before. In this case, the pupil distributes his studying across two or more sessions.
Pupils will retain knowledge and skills for a longer period of time when they distribute their practice than when they mass it, even if they use the same amount of time massing and distributing their practice.
Give mass a miss
Unfortunately, however, many pupils believe that massed practice is better than distributed practice.
One reason for this misconception is that pupils become familiar with the target material quickly during a massed practice session, but learning appears to proceed more slowly with distributed practice.
For instance, the year 7 pupil quickly writes the correct word after practising it several times in succession, but when the same practice is distributed, she may still struggle after several attempts.
Likewise, the year 8 pupil may quickly become familiar with his notes after reading them twice during a single session, but when distributing his practice across two study sessions, he may realise how much he has forgotten and use extra time getting back up to speed.
In both cases, learning itself feels tougher when it is distributed instead of massed, but the competency and learning that pupils may feel (and teachers may see) during massed practice is often ephemeral. By contrast, distributed practice may take more effort, but it is essential for obtaining knowledge in a manner that will be maintained – or easily relearned – over longer, educationally relevant periods of time.
Most pupils, whether they realise it or not, use distributed practice to master many different activities, but not when they are studying…
For instance, when preparing for a music recital, most pupil violinists will practise a piece nightly until they have mastered it; they will not just do all the practice the night before the recital, because everyone knows that this kind of practice will likely not be successful.
Similarly, when playing computer games, pupils see their abilities and skills improve dramatically over time, in large part because they keep coming back to play the game in a distributed fashion.
In these and many other cases, pupils realise that more practice or play during a current session will not help much, and they may even see their performance weaken near the end of a session, so, of course, they take a break and return to the activity later. However, for whatever reason, pupils don’t typically use distributed practice as they work toward mastering course content.
Encouraging distributed practice
To distribute practice over time, pupils should set aside blocks of time throughout each week to study the content for each class. Each study block will be briefer than an all-night cramming session, and it should involve studying (and using practice tests) for material that was recently introduced in class and for material they studied in previous sessions.
To use distributed practice successfully, teachers should focus on helping pupils map out how many study sessions they will need before an exam, when those sessions should take place (such as which evenings of the week), and what they should practice during each session. For any given class, two short study blocks per-week may be enough to begin studying new material and to restudy previously covered material.
Ideally, pupils will use practice tests to study the previously covered material. If they do, they will quickly retrieve the previously learned material after just a handful of sessions, which will leave more time for studying new material.
Of course, pupils may need help setting up their study schedules, and they may need some encouragement to use the strategy. But by using distributed practice (especially if it is combined with practice testing), many pupils will begin to master material they never thought they could learn.
We can also use distributed practice in the classroom. The idea here is to return to the most important material and concepts repeatedly across several days. For instance, if weekly quizzes are already being administered, we could easily include content that repeats across quizzes so pupils will relearn some concepts in a distributed manner.
Repeating key points across lessons not only highlights the importance of the content but also gives pupils distributed practice. Administering a cumulative exam that forces pupils to review the most important information is another way to encourage them to study content in a distributed fashion.
Having explored spaced practice, let’s now consider the importance of interleaved practice.
Interleaved practice involves not only distributing practice across a study session but also mixing up the order of materials across different topics.
Distributed practice is better than massed practice, but the former typically refers to distributing the practice of the same problem across time. Thus, for spelling, a pupil would benefit from writing each word on a worksheet once, and then cycling through the words until each has been spelled correctly several times.
Interleaved practice is similar to distributed practice in that it involves spacing one’s practice across time, but it specifically refers to practising different types of problems across time.
Consider how a standard science or maths textbook encourages massed practice: in a text, pupils may learn about adding and subtracting real numbers, and then spend a block of practice adding real numbers, followed by a block of practice subtracting. The next chapter would introduce multiplying and dividing real numbers, and then practice would focus first on multiplying real numbers, and then on dividing them, and so forth.
Thus, pupils are massing their practice of similar problems. They practise several instances of one type of problem (e.g. addition) before practising the next type (e.g. subtraction). In this example, interleaving would involve solving one problem from each type (adding, subtracting, multiplying, and dividing) before solving a new problem from each type.
One aspect of massed practice that pupils may find appealing is that their performance will quickly improve as they work with a particular problem. Unfortunately, such fluent performance can be misleading; pupils believe that they have learned a problem well when in fact their learning is fleeting.
So, why does interleaving work so well? In contrast to massed practice, interleaving problems requires distributing practice, which by itself benefits pupil achievement but, unlike massed practice, interleaving also allows pupils to practise identifying problems and connections.
When pupils use massed practice, after they correctly solve a problem or two of a certain type, they can almost robotically apply the same steps to the next problem. That is, they do not have to figure out what kind of problem they are solving; they just have to apply the same rules to the next problem.
For interleaving, when a new problem is presented, pupils need to first figure out which kind of problem it is and what steps they need to take to solve it. This is often a difficult aspect of solving problems.
Teachers often demonstrate how to do a few problems (whether writing compound sentences or adding fractions), and then ask pupils to complete a set of similar problems on their own. Pupils learn more, however, when they are given incremental guidance on problem-solving.
In a type of interleaving, problems with written-out solutions should alternate repeatedly with problems that the pupils will solve. Solved problems help pupils focus on the underlying principles that apply to each situation, instead of promoting mechanical solutions to problems. Here’s how it works…
First, we interleave worked example solutions with problem-solving exercises. For example, we could get pupils to alternate between reading already worked solutions and trying to solve problems on their own.
Next, as pupils develop greater expertise, we reduce the number of worked examples we provide and increase the number of problems that pupils solve independently. Finally, we use explanations to accompany solved problems in order to help pupils comprehend any underlying principles, taking them beyond the mechanics of problem-solving.
So practice makes permanent and spaced and interleaved practice works best of all. But what else can we do to help increase the storage and retrieval strength of the information we’ve taught them? One answer is to test pupils, and we will explore this next week.
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