We are all familiar with the expression, “Practice makes perfect.” Almost all teachers take this aphorism to heart and rightly include practice activities as part of their lessons. But just including practice isn’t enough. How the practice is presented makes a big difference in how quickly students will master new material. Here are a few tips that can help you make practice activities as effective as possible.
Distribute practice
It is common for teachers to have students practice a new skill many times just after they have been introduced to it. For instance, I remember from my school days having to write spelling words five times, one right after the other. I’m sure you have seen students do 10 or 20 or even 30 addition calculations involving carrying just after they have had a lesson on this procedure. This kind of massed practice can feel very rewarding because at the end of the effort, most students perform the task successfully, often relatively rapidly. This success, however, is deceptive.
Every waking moment our minds are bombarded with an enormous amount of sensory information. If you walked into the room where I am working now, you would see, for example, that I am wearing a blue sweatshirt, and if I asked you, you could tell me what I was wearing. That information would reside in your working memory, the memory we use to engage our immediate environment, where we have the thoughts we are thinking about at the moment. But if I asked you weeks, or months, or years from now, “What was I wearing on September 14, 2016?” (and you didn’t have access to this blog!) it would be extremely unlikely that you would remember. The information would long have vanished from your working memory without being stored in long-term memory. This same forgetting, in fact, happens to most of the thousands of experiences we have each day.
But of course, even though we forget much, we also are able to remember many things. What mental operations do we perform on the things that we remember that are different from the things that we don’t remember? At heart, it is that we try to remember them! When something first enters the mind, it starts to fade from memory fairly quickly. But when you try to retrieve this information from your memory, the effort strengthens the ability of your mind to remember it in the future. This system works rather well, in that the fact of trying to remember something is a good indication that it is important and worth being remembered.
The deceptive limitation of massed practice is that the new information or skill is practiced only in working memory and isn’t recalled from long-term memory, which is our ultimate goal. While massed practice may have a valuable role at the very beginning of learning something new, forming an enduring memory requires another very important step: trying to remember the new information once some time has elapsed.
And the best time to try to remember the new information is the moment when we are about to forget it. When we are first learning something, that moment is quite close to the time we first processed the information, perhaps seconds, certainly no more than minutes in most cases. But as we successfully remember something, the interval necessary to keep the memory accessible increases quite dramatically, until we are able to retain the information for years. So the most efficient way to commit something to memory is to try to recall it across many intervals of time, ideally, intervals that increase in length. Because this ideal practice is spread out over time, psychologists generally refer to it as "distributed practice."
There is quite about of information about the ideal intervals needed to remember material well, much of it referred to as “spaced repetition.” I encourage you to investigate this technique, and if you are not familiar with computer flash cards programs such as Anki that use spaced repetition, I recommend that you learn more about them. They are an invaluable learning tool
Interleave practice
I’m sure that you have seen practice sessions in which students had to 10 or 20 or 30 problems of an identical type, such as adding 2-digit numbers with carrying, or writing plurals for words that end in “y.” As I mentioned above, with any massed practice like this, the students usually perform the task at a high level at the end of the practice session, and so they and their teachers have a sense of accomplishment.
If the ultimate goal werre, for example, to have a person be able to solve problems when they are told in advance, “All the calculations are sums with carrying,” or “All the words you have to spell involve the pattern of pluralizing a word ending in ‘y,’" then the practice routines I just described might very well be satisfactory. Such a limited goal, however, is almost never what we have in mind. We want people to be able to do all sorts of arithmetic calculations depending upon the situation, and to be able to apply a variety of spelling patterns correctly whenever they write. In other words, the ultimate application of the skill involves a great deal of judgment about what is happening in a particular situation. When very narrow skills are practiced without having to make judgments about the environment, however, students continue to struggle using their new skills appropriately.
There was a fascinating study on this topic done with baseball team at California Polytechnic State University. It is typical for a players batting practice to consist of 45 pitches, 15 fastballs in a row, 15 curveballs in a row, and 15 changeups in a row. At the end of each practice session for a particular pitch, the batter would have “timed up” the pitch and would usually be able to hit the ball impressively. In the Cal Poly study, though an experimental group still received 45 pitches of batting practice, but the pitches were presented in random order. In other words, the batter did not know which kind of pitch he was going to receive. As you can imagine, the immediate performance of the batters in the experimental group suffered because they were not only having to hit a fastball, but having to discriminate whether a particular pitch was a fastball, a curveball, or a change-up. However, their batting during the game improved significantly! I think it is easy to see why. What they really had to do in the game wasn’t just hit a fastball, but to recognize a pitch as a fastball and then hit it. That is to say, there were two things involved in doing the task well, a judgment and a performance. When the judgment was omitted from the practice routine, they weren't practicing the complete skill they needed during a game.
So, as you structure practice routines, you will dramatically improve your students' learning if you interleave different types of items in a practice session. For example, it is much better for students to have practice involving, at the very least, addition and subtraction, and not just one of these operations. This not only helps to distribute practice of material learned earlier, but it forces them to pay attention to the relevant details of the situation (such as what the operation sign is in the equation!). If you want examples of excellent interleaving, take a look at the math textbooks by Harold Jacobs. He wrote most of his books in the 1970’s, before cognitive scientists had done much work on “interleaving,” but he knew nonetheless what a powerful tool it was.
So the lessons for today: to make your practice as effective as possible, make sure that you spread it out over time and that you interleave various kinds of tasks in each practice session.
I'll have some more to say about improving practice routines in my next blog post. See you then!