Interleaving and spacing

Interleaving and spacing

Interleaving and spacing are concepts that I have been researching and implementing for the past couple of years in order to provide students with the best possible chance of retaining their learning.

We are now very much up and running with the new specification, as are many English departments. To our frustration, we are all very much aware that there is now much more content to learn, less time in exams to demonstrate understanding and students now only have that one opportunity to apply their knowledge. Gone too, are the glory days of coursework/controlled assessment. In those days, we would get the coursework done in year 10 and focus purely on exam in year 11. This meant that students only had to retain their exam knowledge for just over two terms. What a dream!

With the new linear model, many of us are starting our GCSE courses part way through year 9 and some of us at the beginning of year 9 in order to ensure all of the content is covered. This therefore means that we are expecting students to retain their understanding, in some cases, for three years before having to apply it in an exam.

Where my journey began?

For me, the difficulty of this became apparent after I’d received ‘star of the week’ for a lesson I was seen teaching. I was seen on a learning walk teaching the concepts of fate and predestination to very low ability year 10. As the door handle went, my heart sank and I instantly regretted selecting such a complex topic for the group. To my surprise the lesson went well and the lowest ability child was able to define the term and apply it to the text. The student therefore demonstrated clear progress. After celebrating receiving a bottle of prosecco with several selfies, it dawned on me that whilst that child evidenced progress in that snap shot of time, it was highly unlikely that they would recall it in two years’ time when faced with an exam situation. To be honest, I’d be over the moon if they remember who wrote the play, let alone how fate and predestination is relevant.

Something had to be done.


Block teaching.

Most of us will be completely familiar with the concept of teaching in blocks. It’s the way we’ve done it, for as long as I can remember. The sad fact is that the students learn only 50% of what we teach them. We can spend hours planning whizzy lessons with cherries on the top, but unless we can ensure students will retain the lesson content, then our efforts are futile.

What is interleaving?

Interleaving is where we mix the chunks of learning up.


Yes, to begin with, it does create a sense of unease but in a beneficial way. Block learning builds a sense of security. Interleaving builds a small sense of anxiety so you take more care over what you are learning and can build links with what you have already taught. Of course this must be done carefully. You wouldn’t for example teach Macbeth on Monday, Jekyll and Hyde on Tuesday, poetry on Wednesday etc. The narratives of the texts would be completely lost. What can be effective however is making the starter relevant to a topic previously taught. The homework may the be on another topic. I’ve provided some strategies below that I have found successful.

The Ebbinghaus forgetting curve

Hermann Ebbinghaus investigated the concept of retention and found that having learned a series of nonsensical syllables, after one month he could only recall 20%. Imagine how this might apply the students in your lessons. When you have finished teaching a topic: what percentage of the learning can they recall? Then imagine you teach this unit in year 9 and two years later, they sit the exam. How much have they retained now?


Spacing: Theory of disuse

When learning is spaced out, students have a greater chance of retaining a larger percentage of the content.

The key is not to simply re-teach content as this is dull not only for the students but for us too. It also can’t be as simple as just re-testing continually. The most effective spacing strategies will use old learning as a platform for further engagement.

Getting started

Interleaving must be planned carefully and strategies should be phased in so not to completely freak out the students.

In my department we began interleaving in a very simple way. Rather than all of spring 1’s content being on ‘Romeo and Juliet’ we have endeavoured to keep content fresh by ensuring that homework is based on a text previously studied for example. Starters may also be based on a previous topic.


Week Main topic Interleaved ‘Do it now’ starter Assessment Homework Interleaved content
1 Jekyll and Hyde 5 a day revision taken from all texts Language paper 1 An Inspector Calls Duality – in the poem ‘Extract from the prelude’ compared to Jekyll

Presentation of London in chapter 1 compared to the poem ‘London.’


Interleaving the content

One of the most beneficial things that we did as a department was to look at our entire curriculum from year 7 through to year 11. We started in year 11 and discussed the topics, themes and skills that came up in each and then made links back to previous years. E.g. Where else does duality come up in the schemes that we teach?

By doing this, we ensured that ‘duality’ for example is not a term that students stumble across in year 11 but is actually a term that they acquired much earlier in their school careers. This exemplifies the ideas of using old learning as a platform for deeper exploration. Rather than learning something new in year 11, students are revisiting old learning and using it as a platform for deeper exploration in relation to a different text.



By interleaving and spacing the curriculum model we are ensuring that students do not simply forget what they have learned but rather it flows through their school life. Neurone’s need to connect to ensure information is retained.

There is no one way to interleave and space and in fact there are many strategies that can be used to help interleave including the Leitner system, chanting, do it now starters and creating the thematic links.

The important thing is to reflect on how these concepts may be applied to our subjects in order to arm our students with the best possible weaponry for succeeding in their terminal examination.

A few strategies:

  1. Homework tasks assess understanding of previous topics
  2. Starters assess student understanding of previous topics. 200 word challenges, do it now starters and 5 a day starters are really useful for this.
  3. Map where themes crop up across texts. When you get to the role of women in Romeo and Juliet: draw on their understanding of this theme from when they studied Curley’s wife for example, or the duchess in Browning’s poem.
  4. The Leitner system has proved particularly beneficial and has been enjoyed by students. They each have a small folder with 6 sections. They have a set of cards that assess their understanding of a text studied. If they answer the question correctly: it moves back a section in the folder. If it is answered incorrectly it moves back to the front. Students follow a rota that dictates which sections should be revised. As the card moves further back it is being committed to long term memory.


Next steps

How can I adapt my LTP to include Interleaving and Spacing?

  • Map themes across texts, schemes, years and Key stages
  • Map what exam style practise you will do and when. Don’t forget to think about how this sits alongside your teaching of the course.
  • Map your homework/starters onto your calendar
  • Ensure this is a collaborative process within your department, otherwise they are less likely to adopt the method.
  • Determine the thematic links within the MTPs
  • Prioritize. It’s impossible to do everything well straight away




4 thoughts on “Interleaving and spacing”

  1. Would you mind if I printed this out to share with my HODs please? We are doing a lot of work on this at the moment and this will support everything we have done so far. Thanks Emilie Williams @TandLCantonian


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