It’s the end of a busy day and a history teacher is preparing for tomorrow’s lesson observation. She knows that senior leaders will be looking for evidence of her applying what she’s learned from the school’s CPD programme. So she casts her mind back. The most recent session she took part in was about whole-school literacy, so this is what the teacher focuses on. She plans tasks with this in mind and diligently explains her thinking in the box labelled “CPD” on the lesson-plan pro forma.

But whole-school literacy isn’t necessarily the most useful area to focus on with this particular class, nor are the strategies best applied in isolation. Yet the recency of the session on this topic is a powerful factor: whole-school literacy is so fresh in the teacher’s mind that it eclipses the previous term’s CPD sessions almost completely.

The culprit here is “recency bias” - a cognitive processing trick our minds play on us by privileging the most recent events at the expense of slightly older ones. New knowledge will be lost as a result, unless it can be assimilated into what we already know.

Why should school leaders care about this? Because recency bias is the enemy of effective CPD. In fact, it’s the reason why CPD models often fail.

When I was a young teacher, my professional development consisted of a parade of standalone initiatives. Some were good, some were bad. But all of them were shiny, new and, most problematically, separate. Most died in isolation as a result. Promising ideas were shunted out of my mind by the next panacea. It was all tactics and no strategy - a form of institutional amnesia induced by a combination of recency bias and cognitive overload.

Did I learn from this? Not nearly quickly enough. Much later, as senior lead for professional development, I fell into exactly the same trap myself. I mistook variety for lively and effective CPD, introducing one new set of evidence-informed ideas after another without building bridges between them. As a result, the teachers I worked with were no more able to overcome the problem of recency bias than I had been.

So how can school leaders make sure that recency bias is not scuppering their grand plans for an outstanding programme of CPD? The key is to take a much more holistic approach. Here’s how to do it.

1. Remember the principles of cognitive-load theory

It is difficult to demonstrate to teachers that professional development is meaningful, because the cognitive effects of our actions are invisibly taking place within our pupils’ brains. It is often hard for teachers to see the direct impact that a new initiative has because when we try to talk about those cognitive changes (learning), we’re only really discussing surface externalisations, such as verbal responses, engagement, motivation levels and behaviour.

John Sweller’s theory of cognitive load provides a window into what is actually happening in our pupils’ brains. Sweller argues that working memory has a limited capacity, so for teaching to be effective, we must avoid overloading it with additional activities that don’t directly contribute to learning (see box, below).

An understanding of cognitive-load theory will help young teachers to make sense of how their actions as a teacher directly affect pupils, making it easier for them to conceptualise how to put CPD into practice. This will provide a sound foundation on which young teachers can build their own knowledge.

2. Create a CPD ‘jigsaw’

To make CPD stick, we need to emphasise the continuous aspect of it by spreading the cognitive load over a linked series of scheduled activities, informed by the latest research evidence and delivered in small staff clusters, overseen by a lead practitioner.

Conventional CPD is full of recency-bias peril until you provide a “big picture” framework, within which staff can track where the evidence converges and put the pieces of the jigsaw together for themselves.

And that jigsaw has to be literal. New knowledge perishes unless we can attach it to what we already know, so teachers need to maintain a mind map or visual representation of their CPD schema as it’s forming. They can refer to this map as their practice develops, using it to justify each and every action they take.

3. Encourage teachers to justify their teaching actions

It should be the objective of all CPD to help teachers to answer the question: “Why do we do what we do?” Continual justification of teaching actions allows us to stabilise our schema and overcome the handicap of recency bias. We need to be a lot more explicit about the conscious choices that we are making in the classroom and verbalise why we make those choices.

From this foundation, staff can slowly build up the branches of their schema to accommodate the implications of new research, introduced through those scheduled CPD sessions.

As their visual schema mindmap grows, the easier it becomes for staff to connect new knowledge to older knowledge and clearly explain their actions. And that means that when it comes to filling in that CPD box on the lesson-plan pro forma, teachers will no longer default to reaching for the most recent thing they have learned - they will instead be able to choose from a web of strategies, supported by a depth of understanding that is stable, yet continually evolving.

Sean Smith is a retired vice principal and freelance journalist

This article originally appeared in the 9 October 2020 issue under the headline “Seeing through recency bias”