Memory: The Number One Thing All Teachers Should Know

Reading time: 4


Ross Morrison McGill founded @TeacherToolkit in 2010, and today, he is one of the 'most followed educators'on social media in the world. In 2015, he was nominated as one of the '500 Most Influential People in Britain' by The Sunday Times as a result of...
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What is the number one thing all teachers should know, and do?

I’ve been reading up on memory for a number of years now, and it is my belief that besides mastering the classroom in terms of subject knowledge and behaviour management, memory is the number one thing all teachers need to know.

I look back on my teacher training in the mid-1990s. Although the 4-year BAEd course put me in a strong position to thrive in the classroom for 25 years, covering everything from child development, behavioural psychology, history of education, theory and practice, there was one aspect of our development that was lacking: How to learn.

How to learn

Many books have rekindled my affair with memory, most recent is Connect the Dots by Tricia Taylor. I have been underlining and ‘red-penning’ sentence after sentence as I ‘subconsciously nod’ to myself after each paragraph. As I write, I’m now more conscious of my implicit and explicit memory as a result, and the statements I am making! I’ve also produced webinars and resources sharing what I have learned…

Reading deeper, I discovered the work of Jeffrey Karpicke PhD, having blogged about some of his research in the past: “Repeatedly retrieving words during initial learning, which amounted to only two or three extra retrievals, produced about a 150 per cent improvement in long-term retention.” The Rule of 3 (2012).

The Wardrobe Metaphor

Another article by Karpicke (2016) “discussed the mental processes involved in the creation of new memories and the recovery of past memories as encoding and retrieval”, exploring how the mind works. In Taylor’s book as well as Karpicke, they both reference the ‘wardrobe metaphor’ which is the best analogy I can think of when explaining how your mind works. “Memories are stored objects in that space; and retrieving a memory is akin to searching for and finding an object in a physical space” (Roediger, 1980).

Note, learning is usually identified with the encoding of new knowledge in memory, and retrieval practice, no matter how good your techniques are in the classroom, are themselves not thought to produce learning. However, as Karpicke writes, “practising retrieval has been shown to produce more learning than engaging in other effective encoding techniques.” Therefore, teachers must build into their curriculum planning and schematic maps, ‘opportunities to retrieve’ in a crowded curriculum which is increasingly pushing teachers and pupils towards a test.

How well would students remember in the long term?

Karpicke shares why retrieval is a powerful wat to improve learning and memory and offers a word-learning experiment in which students learned a list of foreign language words (Karpicke & Bauernschmidt, 2011). The conditions of the experiment are explained: “The students saw a vocabulary word and its translation on the computer screen, and in recall trials, they saw a vocabulary word and had to recall and type its translation.”

  1. Merely studying the words once without ever recalling them produced extremely poor performance, with the average recall was 1 per cent (barely visible on the chart).
  2. Practising until each translation was recalled once was much better.
  3. Massed retrieval – repeating the translations three times immediately – produced no additional gain in learning
  4. Repeated retrieval enhanced learning only when the repetitions were spaced, and indeed, the effects of repeated spaced retrieval were very large.
  5. Simple changes that incorporated spaced retrieval practice took performance from nearly total forgetting to extremely good retention (about 80 per cent correct) one week after an initial learning experience (see also Karpicke & Roediger, 2008; Pyc & Rawson, 2010).

Karpicke concludes, “Unfortunately, many [pupils] do not practice retrieval as often or as effectively as they could.” Repetitive reading is cited as the number one strategy selected by our young people, yet countless research cites that this passive reading produces little or no benefit for learning. All those hours I wasted as a teenager!

Recalling once doesn’t mean you have learned it…

Simple knowledge checks such as questions in class, or being able to recall something in the short term does not mean that there has been a shift in long-term memory. Many students will use a ‘one-and-done’ strategy: “If they can recall something once, they believe they have learned it, so they remove it from further practice”, but the best ways to influence students to remember things, remain to be discovered. And this is what is so exciting about the teaching profession today! However, we cannot waste any more time.

We cannot have all out our pupils still repeating some of the bland revision strategies you and I used for our examinations when we were at school. Rote learning or practice, whatever you call it, are the same thing, and we must equip our pupils and parents which the skills to be able to do this, particularly ‘out of school hours’ during the exam season. Metacognition, quite rightly, has seen a huge growth in popularity in schools as teachers work hard to teach their examination groups ‘how to learn’. However, we must teach these skills – implicit knowledge in my opinion – much earlier on in a pupil’s education.

These teaching techniques are free!

Karpicke again highlights the difference between short-answer questions compared to creating an ideas map (an assessment of the coherence and integration of students’ knowledge). The findings report almost two-fold performance, yet worth noting, using retrieval techniques as part of an ideas map without viewing past text, can also enhance performance. The research also highlights another free strategy: “Closed-book quizzes, which required retrieval practice, were more effective than open-book quizzes, which did not require learners to engage in retrieval.”

Another idea I wrote about in 2015 is Back To Back, a fantastic retrieval practice strategy I’ve been using in my classroom since 2000! And the best news of all is that all these techniques are free! Any teacher can recreate this – no fancy software or theory – just the creativity to design short-term quizzes and techniques in class to help students recall.

The message I decipher from all of this reading and research I’ve conducted is that if you want to improve a pupil’s memory and performance, retrieval is the number one technique to build into your teaching repertoire.


  • Karpicke, J. D. and Grimaldi, P. J. (2012), Educational Psychology Review.
  • Karpicke, J. (2016), American Psychological Association.
  • Taylor, T. (2019), Connect The Dots.
  • McGill, R. (2015) Collaborative Learning.

11 thoughts on “Memory: The Number One Thing All Teachers Should Know

  1. There is a reason that when there are no written records kept people tell stories. We need to help students build and tell their own stories about the things they are learning. I was made aware of this when I shared what I was reading as part of my research weekly with a friend over coffee, once these weekly visits stopped my recall of what I reading was not as good. You are right about metacognition, it is important that we teach pupils how to learn but we must make this an immersive experience and in doing so talk about the emotional aspects of learning too. My take is in developing in pupils their ability to manage their own learning environment to meet their own learning needs. I find we miss this aspect and as a result many pupils self-label negatively. The hero’s journey can be adapted for learning and helps tell the whole story of the challenges, successes, and celebrations associated with learning. You can read my adaption about here:

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