Expanding spacing?

You are no doubt familiar with the idea of spaced retrieval practice. In case you aren’t, it’s the concept from cognitive psychology that if you space out learning and revision episodes over time,  rather than cramming lots of learning and repetition into a single bout of “massed practice” then long-term retention will benefit. The evidence base for this is huge and its effectiveness should chime with your own experience. That’s not to say massed practice is always a bad approach. Like me, you must have seen the benefits of major, night-before cramming before an exam.

In language learning, although there is research evidence which does lend support to cramming input and interaction into a longer episode (you might call this an ‘immersion effect’), the predominant view is that spacing out exposure to input and practice is highly beneficial.

Text book writers are not unaware of this, but in the books I have used they tend to do spacing in a crude manner, notably, leaving long gaps of time before revisiting grammar. (With vocabulary it may be less of an issue since much vocabulary is high frequency and naturally recurs in texts, whatever the topic.) So with grammar, a book might invite you to spend, say, four weeks on the perfect tense, then set it aside for a whole year, by which time classes may have forgotten it. The result is that you have the feeling you are starting from scratch. (In fact, it’s more complex than this, since students may not have been developmentally ready to acquire the new grammar in the first place - that’s another matter.)

When course books don’t fine-tune the spacing well enough, it’s up to the teacher to fill the gaps by revisiting structures, vocabulary or lexical chunks in between text book exercises. This is perhaps one reason why teachers sometimes abandon text books altogether. The perceptive, skilled teacher will complement course book exercises with their own resources and activities.

A reasonable question to ask is this: is there an ideal way to space out encounters with language items? Well, firstly, keep in mind that grammar patterns (some more than others) take longer to acquire or stay in long-term memory than lexis (words and chunks). So it it’s quite possible that vocabulary will be remembered more quickly, with fewer encounters. Indeed, some vocabulary may recalled with just one memorable exposure. Paul Nation and others have tried to calculate how many ‘incidental’ exposures with words are needed for them not to be forgotten. A figure of around 12 has been mentioned, but you have to take this with a huge pinch of salt. Researchers know this. Variables are at play, for example the memory capability of the student and the quality of the encounter (how much was the word noticed, what level of processing was involved, how long did the eye linger on the word). Deliberate teaching of words, chunks and grammar probably speeds up the process.

The general advice from research is that if we get students to interact with a word, phrase or pattern, e.g. by doing something with it, such as write a sentence, the item will be better recalled later. Don’t rely on learning meanings and spellings from lists or apps.

But what about that spacing issue? The Robert Bjork Theory of Disuse posits that if we get to the point of nearly forgetting, even forgetting, something, then reactivate it, the strength of the memory trace will grow. This is why some say that ‘forgetting is good’. That would seem to suggest that you should leave good gaps between learning episodes. Another way of looking at this is to apply the notion of ‘expanding spacing’. Basically this means keeping spaces between early encounters shorter but effortful enough, then gradually extending the gaps. Frank Boers (2021) defines it as follows:

“Expanding spacing means that a first practice session follows a study phase after a relatively short lag, but subsequent practice sessions follow with increasing intervals. When expanding spacing is implemented well, the first retrieval practice will have a good success rate while nonetheless inducing cognitive effort (it should therefore not be done too soon after the study phase). Gradually expanding the interval afterwards helps to keep the retrieval practice sufficiently challenging. Ultimately, however, it is hoped that, as a result of ample practice of the right kind, accurate retrieval will become effortless—and this also during communicative use of the language.”

In a typical MFL lesson you might focus on a range of language chunks, e.g. in a text, texts or sentence builder for a few consecutive lessons, then leave that language behind for a short while before recycling it, then recycle it after a longer gap. In the gaps you are practising other known material, or introducing new language (interweaving old material with new).

But the reality is that in a typical classroom you have 30 students, each one with different prior knowledge, working memory spans, individual motivations, learning preferences and natural aptitude, so deciding when to space learning encounters can only be on a ‘best bet’ basis. You can’t be too scientific about this. What’s more, whatever your curriculum roadmap, you have to adjust your teaching as you go along, observing, as I mentioned earlier, what students can do. Vincent Everett, in a recent blog, likened this to using the Satnav as a guide, but taking the local conditions into account when deciding on your route.

Whatever you do, it’s wise to build in spaced repetition to your curriculum plan. It’s also sensible, I would suggest, to not stick to it too rigidly. Be guided by the students in front of you, what they can remember and what they can do. In addition, as the vocabulary researchers will tell you, keep in mind that repetition is important, but is not enough on its own. Encounters with language items need to be varied, stimulating and often involve doing something with the language to allow more elaborate processing to occur. It’s what Gianfranco and I described in The Language Teacher Toolkit (2016) as thorough and extensive processing. It’s the E in Gianfranco’s EPI methodology (Extensive Processing Instruction), a methodology which is strong on spaced retrieval.

Some readers may feel that second language acquisition is much simpler than this. Provide meaningful language and the opportunity to interact with it and nature will take its course. To an extent I sympathise with this, but in classrooms I think this needs unpacking very carefully. Yes, communication and input are key, but organising how you organise these is a complicated business.

For the Boers reference, see my previous post.