Extract: Developing Expert Teaching by Peps Mccrea

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Date published 02 June 2023

The High Impact Teaching book series pulls together some of the most powerful evidence-informed teaching approaches.

Written by Ambition Institute’s Dean of Best Practice, Peps Mccrea, the series is for those looking to improve upon their teaching practice.

The final instalment, Developing Expert Teaching, explores the practice of teaching, how it works and how to improve it. Peps Mccrea, pulls together the best available evidence from multiple fields to create a framework that you can use to “power up” your own teaching, or that of others.

Below is a chapter from Developing Expert Teaching which explains why developing expertise is important when thinking about professional development.


Why expertise?

“We need to put as much thought into teacher development as we put into student learning.”

— Matt Hood (1)

First up, we need to talk a little about professional development (PD) for teachers.

PD is the best bet we have for improving the learning and life chances of students in our care (2). It’s more cost effective than other approaches to improvement, such as reducing class sizes, restructuring schools, or providing performance-related pay.

And it’s positively associated with desirable teacher outcomes, such as retention, wellbeing, and self-efficacy (3).

Effective teachers build student understanding that is more coherent and abstract than their novice peers—and they do so multiple times faster.

Importantly, these effects extend beyond academic outcomes and benefit those who need it most. Students taught by effective teachers are more likely to attend school regularly, pursue further education, and live healthier, longer lives.

And perhaps most crucially, PD compounds. When we help a teacher get better, every single child they work with from that point on benefits.

PD is not only the biggest lever we have for improving schools—it’s also the most sustainable.

Key idea PD is the most powerful lever we have for improving education.

Developing teachers is hard

PD is important activity, but not an easy one to get right. Despite substantial investment by many education systems around the world (4), much PD fails to reliably turn the dial on teacher effectiveness (and some is even detrimental) (5).

What’s going on? Three major obstacles thwart most PD efforts: task complexity, habit inertia, and a fuzzy relationship between teaching and learning.

Teaching is (mega) complex

Teaching is a complex task. To get a sense of just how complex, let’s compare it with brain surgery.

Brain surgeons are tasked with restructuring parts of the brain that they can typically see, one immobile patient at a time, with sophisticated tools and an ever-present team.

By contrast, teachers are tasked with restructuring the minds of thirty unique children at once, some who don’t want to be there, using only words and images. All of which happens in an environment of limited time and minimal support.

Compared to teaching, brain surgery is a breeze.

Operating in the classroom is one of the most complex tasks ever conceived.

Habits have inertia

In the classroom, we face a vast sea of information to process and decisions to make. To simply survive this situation, it is necessary to automate large swathes of teaching (6).

The more of our teaching we automate—and so run on habit—the more of our limited mental capacity becomes available to make critical decisions, monitor learning, and respond flexibly to student needs as they arise.

Habits are the basis of effective teaching. However, they are notoriously resistant to change, and so also add an inertia to our teaching.

Habits are a double-edged sword which both enable and inhibit effective teaching (7).

A fuzzy feedback loop

When darts players cast a dart, the outcome is immediate and visible. The relationship between action and impact is clear and enables players to make rapid improvement over time.

By contrast, when teachers make a change in their approach, the impact on learning is much harder to discern. This is because:

  • Learning is invisible It is tricky to measure and so can generally only be inferred from student performance.
  • Forgetting happens To assess if lasting learning has occurred, we must wait several weeks after we last taught it.
  • Multiple factors are at play Even if we could measure learning, it would still be a challenge to isolate exactly what caused it.

Compared with darts, the relationship between teaching and learning is fuzzy, making it hard for teachers to improve via experience alone (8).

Trial & error, reflection, and discovery are simply not powerful enough to cut through the fuzz (9). We need better tools (which we’ll talk about shortly).

With these obstacles in mind, the high failure rate of PD starts to make sense.

Key idea Developing teachers is hard.

If we want to execute PD with confidence, we need an approach which can systematically overcome these obstacles, and that can also do so with much greater odds of success.

It’s time to bring expertise into the story.

Expertise holds the key

In the 1940s, a group of scientists started investigating how chess players got better.

This spawned a field of research which would go on to generate hundreds of empirical studies across multiple disciplines—such as music, sports, and medicine—and gradually eke out a robust explanation for how people excel in their field (10).

Crucially, this study of expertise offers us a theory of change—an explanation of how certain PD experiences lead to improved student outcomes. And it does so in a way that takes account of both the content and process of PD, something our profession has struggled to achieve to date.

In short, the insights generated from expertise offer the best available foundations upon which we can build a reliable framework for teacher PD.

Which is exactly what this book intends to do.

Key idea Expertise is the most powerful way to think about effective PD.


Chapter summary (key ideas in bold)

  • PD is the most powerful lever we have for improving education; it is more sustainable and cost-effective than other approaches.
  • Developing teachers is hard; understandably so, due to task complexity, habit inertia, and a fuzzy relationship between teaching and learning.
  • Expertise is the most powerful way to think about effective PD; it gives us a (rare) empirically grounded theory of change around PD.

Notes & further reading*

  1. Quote from Beyond the Plateau: The Case for an Institute for Advanced Teaching
  2. Note: effective supporting curricula are equally important—for more, see What We Teach Matters, by Learning First
  3. For a more comprehensive analysis of this argument (and generally ace book), see Leadership for Teacher Learning, by Wiliam
  4. For an estimate of the investment in PD (in the US), see The Mirage, by TNTP
  5. See The Effects of High-Quality PD on Teachers and Students, by Fletcher-Wood
  6. Check out Habit Formation Limits Growth in Teacher Effectiveness, by Hobbiss
  7. Phrase from Cognitive Load and Classroom Teaching, by Feldon
  8. For further nuance, see The Myth of the Performance Plateau, by Papay
  9. This is what Kahneman calls a ‘low validity environment’. For more, see Conditions for Intuitive Expertise: A Failure to Disagree
  10. For an origin story, see Expert Performance: Its Structure and Acquisition, by Ericsson

* For links to all readers, visit pepsmccrea.com/expertise


Read more about Peps' work on his website here.

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Peps Mccrea
Dean of Best Practice

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