6 – Spacing Theory

We acquire language when we repeatedly retrieve it in spaced intervals.

You have a BIG test tomorrow, but you haven’t studied yet. You think, “What am I going to do?” And your friend Joe says, “You have to pull an all-nighter.” You say, “Oh no! I have to study all night again!”

You set out your books on your desk. And you start to study hard. At about three in the morning, you decide to take a break. You lay down on the floor on the hard green carpet. And the next thing you know, you wake up at 8:37 A.M. You have just enough time to run to class and take the test.

After the test, Joe comes up to you. He doesn’t ask you about the test, but he says, “What happened to your face?” You pull out your phone and look at your face with the camera. The left side of your face is covered with the pattern of the carpet. You say, “I fell asleep on the carpet at three in the morning. When I woke up, the carpet had pressed its pattern on my face.”

Joe says, “Well that’s what happens when you pull an all-nighter.” Actually, that’s not the only thing that happens. When you study all night the day before the test, we call this “cramming for a test.” And scholars also call it “massed practice.” This means you do all your study or practice for a test in one mass session. With massed practice, maybe you will pass the test, but you will also probably forget everything you study.

Experts say that spaced practice is better than massed practice. With spaced practice, learners do retrieval with spaced repetition. We also call this spacing. With spaced repetition, you don’t just study or practice during one mass session. You have many practice or study sessions. And you do spaced repetition with retrieval. Remember what we read about retrieval in Chapter Five.

If you re-read a textbook and review notes, you might think you learned the material, but you really didn’t learn it! You only familiarized yourself with it. To really learn something, you need to show that you can retrieve it from memory without looking at the textbook and notes.

Let’s look at retrieval with spaced repetition for word card study. Imagine you are studying English and you are a native speaker of Japanese. You have a set of word cards with target English words on one side and Japanese on the other side. You look at the Japanese translation, and you try to retrieve the English from memory. If you retrieve correctly, you put the card in the “I know” group. If you fail to retrieve a word correctly, you put it in the “Not Yet” group. You go through a set of cards, and then you put them in your pocket.

Now you take a break from word card study. When you are not studying, we call this a “space.” During this space, you probably start to forget the words that you studied. Two days later, you do retrieval again with your word cards. You move some cards from the “I know” group to the “Not Yet” group because you forgot them. And you move some “Not Yet” words to “I know.” You repeat this process until you know all the words. Now you have done retrieval with spaced repetition, which works better than massed practice. You also do not have a carpet print on your face.

In the word card example, we see how productive retrieval works with spaced repetition. Now let’s look at how receptive retrieval works with reading (or listening) for language learning. As readers comprehend stories, they receptively retrieve the meanings of words, phrases, and grammatical patterns. And they do this with spaced repetition. That is, readers meet and understand common words and grammar patterns that are statistically spaced throughout stories and texts. In this sense, when readers understand, they receptively retrieve ┬áthis understanding. That is, understanding = receptive retrieval.

Here is a basic point. Learners can get a lot of understandable input through reading or listening. When learners get this big input, they experience receptive retrieval of lots of language with spaced repetition. That is, receptive retrieval + spaced repetition naturally works with lots of natural language input.

Now we come to a finer point. Readers will experience more spaced repetition of high frequency words and grammar patterns than with low frequency words and grammar patterns. For example, let’s look at a mid-frequency word like “satellite,” which is about the 5000th most common word in English. A reader will have to read 1,321,429 words of unsimplified text to meet this word 10 times (Waring, 2009). If a reader meets “satellite” 10 times, she will probably acquire it incidentally. Thus, for mid and lower frequency words, readers may not easily meet them enough for spaced repetition to easily work its magic.

However, this factor is made more complex by the learning mechanisms of more advanced learners. Elgort and Warren (2014) claim that more advanced learners acquire vocabulary more efficiently than lower level learners, so that we may see a “Matthew Effect” (Stanovich, 1986) where lexically rich learners get lexically richer. That is, a richer vocabulary predicts faster and more efficient word learning. The more words we know, the quicker we learn new words. Thus, for lower frequency words, more advanced readers need to meet them fewer times to acquire them incidentally.

We can see clear reasons for this. Imagine a learner knows the mid-frequency words “lion” and “tiger.” Now, “having accrued statistics about words such as LION and TIGER allows the listener (or, later, the reader) to infer much about the meaning of a new word such as LYNX when it occurs in those contexts — without being told” (Seidenberg, 2017, Chapter 6, Section 5, para. 8). The advanced learner uses contextual knowledge about “lion” and “tiger” to infer the meaning of the similar word “lynx.”

Here’s the final point. Spaced repetition works differently with lower frequency items because advanced learners have a web of pre-existing word knowledge that helps them more efficiently learn lower frequency items. However, we can consider spaced repetitive learning a strong factor for learning high frequency words and grammar patterns that readers will meet as they read or listen to language extensively.


Dr. Joseph Poulshock

Dr. Joseph Poulshock works as Professor of English Linguistics in the Faculty of International Communication at Senshu University.