Spaced Retrieval

Resources, ideas and prompts for discussion related to Deliberate Practice and retrieval based tasks

Planning learning over time to make remembering more likely

Two key features that have emerged from applying evidence from cognitive science to classrooms are spacing and interleaving. Spacing refers to leaving sufficient lapses in time between practising in order to better remember material. Interleaving refers to alternating between problems over time, as opposed to traditional ‘blocking’ where topics or problems are dealt with in one go. This does challenge thinking as for spacing and interleaving to work as well as it should (and can!) conventional approaches to organising rotas or mid-long term plans have to be more flexible. The infamous ‘Ebbinghaus Forgetting Curve’ is commonly used to illustrate the point of strengthened retention over time with spaced retrieval.

What is the Ebbinghaus forgetting curve?
Ebbinghaus Forgetting Curve for Retention of Newly Learned Information

The challenge is striking that balance; between a) teaching for mastery and spending enough time on one topic, and b) teaching for memory by building in time to revisit topics. Damian Benney has blogged about his approach to this in ‘Spacing, Interleaving, the Testing Effect and Distributed Practice (The Diet Coke Version)’. There are also practical approaches to make it manageable based on a ’15 Minute Forum’ presentation by Andy Tharby and blogged about at

How might it look in design?

As far as interleaving is concerned the below diagram shows a possible representation in contrast to blocking.

Image developed by David Didau

Despite it being shown to be far more beneficial for memory gain over time than massed blocking approaches, it stubbornly gets reported that it feels like it isn’t working by learners and teachers ‘in the moment’. Consequently it is often found that there is a reverting to traditional blocking. However the interleaving and spacing design approaches can be applied to practice, if not content delivery. After you have introduced a new concept or topic, set quick quiz questions not just on this topic but mix them with questions about last lesson’s topic, last week’s/month’s/term’s and so on.

Another idea is to periodically and transparently set cumulative assessments, as this will aid recall and retrieval and also better model the experience of terminal exams. We often set a test or formal assessment at the end of chapter in most subjects. Instead if you have reached the end of Topic 3 for example, design an assessment that will test Topics 1, 2 and 3 combined.

Timely reviews

‘Teaching Walkthrus’ also considers the positive impact of spaced retrieval and reinforces much of what has been discussed above, encouraging teachers to:

  1. Generate study materials with students, be it revision notes, class notes, diagrams, knowledge organisers, readings on topics. All the things they would need to review and revise in future.
  2. Plan for the spaced out practice, make a decision when and how often you will conduct the recap quizzes and try to be consistent (note it in planning just as we would make a note of when to set home learning). Also decide how often you will recap just the recent lessons and when you will perform longer ranging recap quizzes.
  3. Choose your activity, this may well be a quiz but doesn’t have to be. Learners could produce a mind map, produce a writing piece, solve a problem, or discuss with peers, based on a topic covered at some previous point in time.
  4. Spot the memory gaps, look out for the common errors that crop up, the things that seem to have been poorly remembered or mis-remembered and then quickly remind/repeat these (fill in that memory gap). If it uncovers a major problem then this could inform your planning and you may decide to re-teach something in a coming lesson for 10-15 minutes.
  5. Illuminate any connections, when reviewing the answers if there is a topic that now links to something else that been covered since then make a point of making the point! Connections help us create sense of the content being covered.

Further practical strategies for lessons

The Retrieval Practice ‘Grab bag’ page in this section has many more resources to aid recall and memory. One example covered here though is an excellent suggestion from ‘Retrieval Practice: Research & Resources for every classroom’ by Kate Jones (copies available in the MACS CPD Library). It uses Retrieval Practice Challenge Grids. This task combines retrieval, spacing and interleaving (jackpot!), and are often used as starter/Do Now style tasks though can be used at any time.

Before we go on, if you like these and want to make your own, Mark Anderson ( has made a ‘blank grid’ freely available in 3×4, 4×4 and 5×4 sizes. Download the PowerPoint template here.

Here is one of Kate’s own examples from History:

from @87History (Kate Jones)

Here is an example from PE by Tom Brush (Twitter: @tombrush1982)

from @tombrush1982

As you will note, the grid is filled with key questions and those that are drawing on topics from further ago attract more points.

Kate explains in her book how she has herself, and also received examples from others who use this as an extended task at times, beyond a starter activity, and could last a whole lesson. This could be particularly useful for exam preparation. As an example this grid was produced and used by Jancke Dunne (Twitter: @awaken_english) to help students revise and prepare for an A-Level English Literature exam.

Retrieval Challenge.PNG
from Jancke Dunne @awaken_english

The intention would be to have electronic copies of these materials to re-use and tweak in future, as Jones notes to do them well it can take some time and thinking on behalf of the teacher to create a good quality grid of questions, covering topics from a range of times. To save time she recommends building a bank of quick quiz questions that would normally be used for regular quizzing and saving these in a document so selections can just be copied and pasted into a grid.

Alternatively a really simplified approach is to use something like the grid below:

Last lesson:

Last week:

Last term:

Last year:

Simple spaced retrieval challenge grid

Instead of creating a larger grid with questions, you could just choose 4 topics or ideas in advance from the relevant time scales and ask students to complete a mini ‘brain dump’, for each committing all they remember to paper in the spaces, either on their own or in collaboration with a peer (Brain or Memory Dumps are covered more here). This is simple, still promotes the same principles and encourages recall and also allows for highlighting knowledge gaps.

Associated further reading and references:

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