How to Explain Absolutely Anything to Absolutely Anyone: The art and science of teacher explanation

Introduction

Daddy, in football, is a striker the same as a forward?

Daddy, why do we have wars?

Daddy, what would happen if all books were made of bacon?

From the age of about two, children develop the intellectual ability to ask why questions. It is a vital developmental milestone. Their burgeoning curiosity about the world and their increasing proficiency with language means that they become desperate to learn more. To quench their new-found thirst for knowledge and understanding, they seek answers from the adults in their lives; their parents and teachers. They are becoming aware of what they do not yet know, or have not yet imagined, and they go on a tireless hunt for the further information and elaboration that might lift the veil on the mysteries of the universe. George, my 6-year-old son, asked me the three questions above over the period of time I spent writing this book. (Be assured, this book is suitable for vegetarians!)

Nothing could be more natural to human language and communication than explanation. Explanations have a range of purposes: to make something understandable; to clarify and expand an idea; to give the causes, context and consequences of a situation or event; or to show how facts and concepts are related and connected. The most straightforward definition of an explanation is ‘the answer to a question’. As members of language communities, we provide and receive countless explanations every day, at work and at play. This is why the word ‘because’ is one of the most important in the English lexicon. If the question is ‘why’, the explanation finds its origin in ‘because’.

It is near impossible to conceive of effective teaching without explanation. A teacher who does not explain is little more than a mute babysitter. However, classroom explanations – also known as ‘instructional explanations’ – are more problematic than those that occur spontaneously in the course of ordinary life. This is because the recipients of the explanation, our students, have not previously sought out the new information that we require them to learn. Sometimes, they are not aware of what they do not know. More troublesomely, they sometimes hold misconceptions which mean that they are completely convinced of an alternative and inaccurate ‘truth’ to the one we hope they will learn. Sometimes the problem lies in a lack of motivation, especially when students fail to see the relevance of the new material that we are trying to explain.

It would seem sensible, then, to assume that if young people are to learn about the nuances of tectonic shift or the finer details of atomic structure, their teachers should learn how to explain these ideas with clarity, precision, flair and agility. It would also seem sensible that a sizeable portion of teacher training and development be dedicated to helping teachers to improve their ability to explain these concepts. Sadly, this could not be further from reality. In recent years, teacher talk – the most efficient form of explanation known to man – has become the black sheep of the education world. In some schools, teachers have been encouraged to talk less so that their students can talk more. Group-work and student-to-student discussion have become the gold standard, lauded and applauded despite their considerable limitations when students are working with new material. Teachers have been discouraged from speaking for too long, and in some cases have been hung, drawn and quartered for doing so!

Thankfully, the tables are beginning to turn. Common sense and research evidence are converging to reassert the importance of the teacher’s role in the classroom and, more significantly, the importance of the things that the teacher has to say. In 2014, teacher and writer Daisy Christodoulou’s Seven Myths About Education methodically dismantled many prominent misconceptions about teaching and learning. In response to those who argue that teacher-led instruction is passive, Christodoulou wrote:

There is a reason why it took humans such a long time to discover the laws of nature, even though the evidence for such laws was all around them in the environment. We do not find it easy to learn new information when we have no or minimal guidance.¹

Each new generation stands on the shoulders of the last. Few young people can understand the theories of Charles Darwin and Albert Einstein, or fully appreciate William Shakespeare and Mary Shelley, without guidance and explanation from an expert teacher. It is essential that teachers feel confident enough to stand up at the front and teach such world-changing content without the accusation of being didactic or overly dominating. There is a time for teachers to talk; and there is a time for students to listen. Of course, there is also a time when the reverse is more desirable and students should be working independently and autonomously. But this should usually happen towards the end of a sequence of learning, not at the beginning. In most cases, teachers should first provide answers and then open the space for interrogation.

A wealth of empirical evidence supports the assertion that teacher explanations perform a crucial role in learning. Educationalist John Hattie systematically analyses the effectiveness of different influences on learning. At the time of writing, his most recent list of 252 separate influences placed ‘teacher clarity’ at a very significant number 24.² John Hattie and Gregory Yates have also shown that teaching is much more effective when teachers use methods that activate learning rather than methods that facilitate learning.³ Put simply, students usually learn better when a teacher introduces new content rather than attempts to elicit it from them. Moreover, evidence from cognitive science reveals that the less prior knowledge a student has about a topic, the more teacher guidance they need. Human cognitive architecture is simply not designed to learn difficult new concepts independently.⁴ Further evidence points towards the constructive influence of face-to-face interaction between teacher and student. For instance, one study shows that students’ learning and persistence outcomes are better when they take in-person courses than when they take online courses.⁵

Needless to say, not all teacher talk is effective talk. Too often, simple concepts are made too complex and complex concepts too simple. Students can be left uninterested or overwhelmed. We must also stay vigilant against a pair of familiar adversaries: decreasing attention and wandering minds. Even though verbal explanations are a staple component of almost every lesson, it is also well-established that they do not always work for all students.⁶ However, this does not mean that teachers should limit their talk; it means instead that they should learn how to talk better. Explanations are to teaching what penicillin is to medical practice: essential but not effective in every case.

Research into effective teaching also reveals some fascinating and quite counterintuitive insights. In the US, Professor Siegfried Engelmann has compiled over half a century of evidence supporting Direct Instruction, a model of teaching that involves scripted explanations. Engelmann argues that what children learn is totally consistent with the input they receive from a teacher. Direct instruction involves precise clarity of wording, the use of carefully designed examples, and the teaching of rules and ‘misrules’ – all delivered through a systematic trickle of new information. Direct Instruction is a mastery approach to learning, which means that 85% of lesson time is devoted to practising material that children have already covered, while only 15% involves weaving in new material.⁷ A nine-year longitudinal study called Project Follow Through found that students who received Direct Instruction had significantly higher academic achievement, better problem-solving skills and higher self-confidence and self-esteem than students receiving any other type of instruction.⁸ Engelmann’s slow and careful methods are a far cry from the rush and clamour of the way the curriculum is delivered in primary and secondary schools in England.

Before we start to explore the how, let’s take a moment to think about what we might be trying to achieve each time we launch into an explanation. Chris Anderson, the curator of the non-profit organisation TED, gives this advice to would-be public speakers: Your number-one mission as a speaker is to take something that matters deeply to you and to rebuild it inside the minds of your listeners.⁹ This ‘rebuilding’ metaphor is essential to our understanding. The most effective explanations are designed and crafted with subtlety. As with the most robust physical structures, explanations should be built to last. The content we teach – whether it’s quadratic equations or the respiratory system or dramatic irony – is not only for understanding and admiring now, but also for storing away for the future. A new fact, concept or idea is a gift for life, not a short-term loan.

There are many different types of instructional explanation. Teachers routinely explain facts, concepts, procedures, moral and aesthetic truths, metacognitive strategies and more. Each type of explanation comes with its own distinctive set of tricks and skills and a corresponding collection of hitches and hazards. We will explore these in full as we move through the book.

Explanation is an art form, albeit a slightly mysterious one. We know when we hear and see a teacher unravelling a great explanation. It has something to do with their effortless subject knowledge, the simplicity and directness of their language and the sense of assurance they exude. Nevertheless, we struggle to describe the intricacies of the craft. Just how exactly are they doing it? Invariably, we attribute good explanation to elements of a person’s character or talents: they’re so confident or they explain things really clearly or they know their subject really well. However, these assumptions are unhelpful because they suggest that the ability to explain is a God-given gift; a form of tacit knowledge that some possess and others do not. In fact, explanation involves a set of intricate tools that anyone can master with a little patience and practice.

To unveil these hidden mysteries we will dip our toes into several forms of evidence. We will draw from educational research, from curriculum theory, from cognitive science, from the study of linguistics, from communication studies, from ancient philosophy and from the expertise of great teachers. We will look at how the most effective speakers, presenters and writers can transform even the most messy, complicated idea into a thing of wondrous crystalline clarity. And lastly, I will share some anecdotal accounts from my own English lessons of how I have attempted, often clumsily, to improve the way in which I explain new ideas in my classroom.

The idea of writing this book came to me on a rainy Saturday afternoon when I was halfway through the first chapter of Carlo Rovelli’s Seven Brief Lessons on Physics.¹⁰ I had wanted to read a book about physics for a while; it is a subject I know very little about and one that has always somewhat intimidated me. I was struck immediately by the way in which Rovelli welcomed me into this new and potentially hostile world. Suddenly, the theory of relativity – for so long the impenetrable playground of wiry-haired science types – was something that even I, in my limited way, could begin to grasp. But more than that, it was lucid, strange and enticing. Beautiful even. I wanted to find out more.

How did Rovelli paint this new world so vividly? Let’s begin with his bluntly put first sentence: In his youth Albert Einstein spent a year loafing aimlessly.¹¹ Immediately, Rovelli opens a gap between expectation and reality by disrupting our conventional beliefs about Einstein: he seems more like a conventional teenager than a prodigious genius-in-waiting. Rovelli then plants us in a very specific time and place: Italy at the turn of the nineteenth century. Success stories are driven by obstacles that stand in the way of the protagonist’s goal, and Albert’s story as it progresses is no different: his theory of relativity did not fit with what we know about gravity, namely how things fall.¹² In fact, Einstein had found himself – theoretically at least – pitted against a titanic foe: Isaac Newton, the godfather of Western physics.

After framing his narrative, Rovelli pops himself into the story. He recounts the moment on a sunny beach in Calabria where, in the pages of a mouse-gnawed book, he finally appreciated the magnitude of Einstein’s theory. Looking up from the book and out to sea, Rovelli envisaged the curvature of space and time¹³ as Einstein described it. This is an emotional and finely drawn epiphany – note the wonderful contrast between the tatty, nibbled book and the unimaginable greatness of the cosmos.

As he moves more deeply into scientific theory, Rovelli brings the mysteries of reality alive through metaphor. Space is described as a gigantic flexible snailshell, the earth as a marble that rolls in a funnel. Other sentences are written with remarkable economy: The gravitational field is not diffused through space; the gravitational field is that space itself.¹⁴

Rovelli’s short chapter includes many of the tools vital to a great explanation: an interesting story; a clear context; an unsolved problem; a personal involvement; a journey from the concrete to the abstract; the precise use of metaphor to capture hard-to-imagine concepts; and a vividness and economy of language. Teachers can certainly learn a lot about the art of explanation from reading books on complicated topics written for a lay audience, like Rovelli’s.

Needless to say, skilful classroom explanation is about much more than word choice and the odd deft figure of speech. For example, students arrive in our classrooms with widely differing prior knowledge, which then influences how much they can comprehend and commit to memory. Furthermore, the language of many subjects, such as mathematics, goes far beyond spoken and written English. Images, diagrams, graphs and visual organisers are part and parcel of the symbolic code of learning. We should also be clear that explanations are not lectures. Ideally, they involve a dialogic process that involves active listening and participation from every person in the room.

A teacher’s use of language also has a wider purpose: to induct students into the academic discourse of each subject. Think of each subject as having its own grammar; its own language world. This is a set of language conventions – involving phraseology, syntax, vocabulary and idiomatic expressions – that reflects the kind of thought processes