5. Teacher exposition

Video transcript

Presenter intro: Helena Moore

A lot of what we teach our pupils will be new or abstract, and it can be difficult to learn. To help with this, teachers can explicitly teach the knowledge and skills that pupils need to succeed. Exposition is the part of a lesson where the teacher can explicitly teach their pupils. This includes explaining, modelling and demonstrating. Exposition provides an opportunity for teachers to set things out clearly.

Presenter main

Exposition is the part of the lesson where the teacher carefully shares material with pupils. Think of it as the I part, where I refers to the teacher sharing something with their pupils. Our working memories, where conscious thinking takes place, have a limited capacity and can become overloaded, especially when dealing with unfamiliar content. Good expositions support pupils to think by breaking knowledge down to steps, highlighting key ideas, and building on what pupils already know.

Depending on the content, teachers may want to choose between the following modes of delivery: explaining, modelling, or demonstrating. Different modes will suit different content.

An explanation is where we clearly tell students some information. This works well for explaining a concept. One approach is to give a carefully worded definition, and then a couple of examples. In a primary maths lesson, this might mean showing pupils an empty bottle of water and explaining that capacity is the amount that something can hold. In history, this might mean explaining what propaganda is followed by an example of a propaganda poster used in the first world war to encourage women into the workplace. Another approach is to use a concrete example, such as number blocks for visualizing tens and units. Teachers can use the concrete examples to illustrate abstract concepts like addition.

Modelling is where we work through a process, articulating the steps and our thinking process as we go. In an English lesson, a teacher might tell pupils that a topic sentence introduces the main idea of a paragraph, and share their thought process out loud, like “I’m looking for the first sentence in the paragraph”, as they scan a paragraph on the white boards. Sometimes a visual representation of the concept or process that you’re modelling helps pupils to understand the material.

Demonstrating is where a teacher uses the physical object to show a process or a concept, such as how to use shade with charcoal pencils, or how to use a ray box, slit and lens to see how different surfaces refract light. As the teacher demonstrates, they draw our attention to the important features and the most relevant thought processes.

To be effective, expositions need to be carefully planned. At the planning stage, teachers can identify what they want pupils to know or be able to do. They need to do this in detail. One approach that can be helpful is to complete the following sentences: “I want my pupils to know that…” or “I want my pupils to be able to…”  Being granular and specific at this stage will improve the clarity of expositions.

Teachers also need to ask themselves where their pupils’ current starting point is. Expositions should build on what pupils already know. This will help them to access the content and link it to existing knowledge.

Finally, teachers need to plan out what they say in advance. Scripting expositions is a good idea.

To get the best out of an exposition in the lesson itself, pupils need to think hard during it. To promote this, teachers can ask questions during the exposition. Questions can draw attention to the key features of the example, model or demonstration, and they can also check for pupil understanding.

Overall, pupils shouldn’t be passive during an exposition.  Instead, they need to think about the new content they are learning. Only then will they be able to use it independently, an important goal of good expositions and effective teaching.

Presenter exemplification framing

In a moment, you’ll see an Ambition Institute coach give an example of how to model during an exposition. Pay particular attention to the following as you watch:

  • Start expositions at the point of current pupil understanding
  • How modelling provides more structure for learners early on in the domain

Exemplification: Ambition Institute Coach

In this example, I’m going to model how teacher exposition can support pupils to learn.  I want you to imagine I’m teaching a year four geography lesson, and this is part of a series on ordinance survey maps. In this lesson, pupils will learn how to use four figure grid references to locate places on a map.

“Okay, class, last lesson, we looked at ordinance survey maps, and how people can use them. But this lesson, we’re going to be looking at how we find certain things on the map.

Okay, before we get started, I’d like to draw your attention to three things on the map.

The first is that the map is divided into squares [teacher points to squares on map].

The next thing is that we’ve got a horizontal line along the bottom. This is called the eastings, and it’s numbered, 74, 75, 76, et cetera [teacher points to eastings line].

And the final thing is that we’ve got a vertical line up the side. This is called the northings, and this is also numbered, one, two, three, and so on [teacher points to northings line].

So when we want to help somebody find something on a map, we give them a grid reference.  This is a four digit number and it’s made up of the eastings and northings line numbers. So rather than somebody having to look on the map all over to find the thing that you’ve told them to look for, instead, we give them the four digit grid reference. And this is what I’m going to teach you today, how to create that four digit number.

Okay, so the first thing I’m going to do is decide on a symbol that I’m going to be looking for. I’m going to use the symbol P, what does the symbol P mean? Aisha?

[Pupil gives correct answer]

Parking, super. Okay, so the first thing I do is I highlight the square that has my symbol in, and then I’m going put a cross in the bottom left hand corner, you will see why in a moment.

So, remember those lines we were talking about, the eastings is the first one we start with, along the bottom, the horizontal.

[Teacher drawing on map on board] So we go along the bottom until we come in line with that x that we just drew. And now look at the number, 77. So this forms the first part of my grid reference, and I put a comma after it. The next thing I do is I then look at the northings. So I’m going to now go up until I hit that cross again. And I look at the number here, 05. So this goes here after the comma, one, two, three, four, that’s my four digit grid reference number.

So there’s a couple of things I like to remember that helps me get these numbers in the correct order. We have to put eastings first and northings second, so I remember along the corridor and then up the stairs.

Let’s do a couple more together, using that to help you remember the order they go in.”

I want to draw your attention to a couple of things in that model. First, let’s think about how I use pupils’ current understanding as a starting point for the exposition. So, from the previous lesson, pupils know that a map is designed to help people navigate to somewhere. Knowing that maps are designed for navigation gives a meaningful and concrete purpose for the grid reference task. I also used the terms vertical and horizontal when introducing pupils to the new terms. I know that we’d learnt the terms vertical and horizontal in maths and art.

Secondly, I explained and modelled the process of given a full figure grid reference to scaffold and support the learning. I used non-verbal gestures like tracing around the square with my finger to reinforce what I wanted the pupils to focus on, and I articulated my thought processes out loud, like always start from the bottom left hand corner. In doing this, I provided pupils with clear steps to follow, which is a really useful structure for their thinking. As I provide further examples that model and demonstrate this process, this is going to help pupils become familiar with identifying symbols and locating places of interest using the grid references. We’ll work on these examples on the board, practising a range of examples together before moving on to the independent practice.

By modelling the process that we want pupils to engage in clearly, we can help to support and scaffold the new learning.

Presenter key ideas

In this video, we have explored how exposition can be used to support pupils to access content. Expositions are especially important for setting up new or complex material. Before we finish, read through the key ideas of the module. Which of these have you applied in a recent lesson?

  • Using modelling, explanations and scaffolds, acknowledging that novices need more structure early in a domain
  • Starting expositions at the point of current pupil understanding
  • Combining a verbal explanation with a relevant graphical representation of the same concept or process, where appropriate

Presenter summary

Teachers are likely to use expositions in the majority of lessons they teach. They might explain, model or demonstrate. It’s a key instructional tool, which at its best can make content much more accessible and increase the chance of success.


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Teaching challenge

Ms Thomas is confident about what her pupils should learn. However, when she tries to convey new content to pupils, she struggles to keep their attention: if she gives a quick explanation, she gets lots of questions and confusion, but if she goes into a lot of detail, she fears pupils will stop listening. How can Ms Thomas most efficiently support her pupils’ thinking when conveying new ideas in her lessons, and get a sense of whether pupils have understood?

Key idea

Effective exposition uses models, concrete examples and is matched to pupils’ needs.

Evidence summary

Effective exposition

Effective teaching takes account of the limits of pupils’ working memories. Pupils may struggle if they experience cognitive overload: this is particularly likely if pupils are exposed to too much new material at once. Ms Thomas can manage pupil thinking effectively by introducing material in stages by:

  • Drawing on prior knowledge, explicitly linking to what pupils have already been taught.
  • Breaking material up into smaller chunks when introducing it to reduce overload.
  • Structuring her teaching around an ‘I-We-You’ model. This should begin with what pupils already know; provide them with a clear explanation of the key ideas and demonstration of the task (I do); provide an opportunity to practise the task collectively and for the teacher to check pupil understanding (We do); and finally move to pupils working independently (You do) (Lemov, 2015).

The I-We-You structure provides multiple opportunities for teachers to convey new ideas by using concrete examples, modelling, and worked examples (Lemov, 2015). These place manageable demands on pupils’ working memory, supporting them to actively process and understand new material (Deans for Impact, 2015).


When should Ms Thomas give explanations? Explanations are more effective when teachers want to convey concepts rather than processes (Wittwer & Renkl, 2010). However, the examples teachers give are more important in pupils’ understanding than the explanations accompanying them (Wittwer & Renkl, 2010). Ms Thomas wants her pupils to understand both concrete ideas (things they can visualise, like ‘numbers as counters’) and abstract ideas (things with fewer sensory properties such as ‘multiplication of numbers’).

She can best convey this to her pupils by using concrete examples in her exposition (ideally linked to current pupil understanding) and connecting them with more abstract ones, or by moving from concrete to abstract representations over time (Pashler et al., 2007). For example, she may introduce multiplication using counters and then remove these as pupils gain understanding of multiplication as an operation. Pupils find it easier to process an explanation where images are paired with spoken words, rather than where images are accompanied with extensive written text (Pashler et al., 2007).


Concrete examples can help Ms Thomas to introduce new concepts. What about new processes? When learning how to solve problems, pupils need support with their thinking through modelling. When teachers model and think aloud while demonstrating how to solve a problem, this provides cognitive support (Rosenshine, 2012). Modelling can be done in a variety of ways; the goal is to give pupils a scaffold while they are a novice before gradually removing it as their mental model develops.

For Ms Thomas, modelling might involve talking her pupils through each step of a new problem in maths. For writing an essay it might involve talking through the decisions she would make in writing. A particularly powerful form of modelling for new processes is providing a worked example that the teacher walks the class through. Novices who are provided with worked examples when learning a new problem outperform those without them (Sweller, 2016).

Worked examples reduce cognitive load by providing scaffolding to help pupils break a problem into chunks, allowing teachers to introduce the problem step-by-step (Deans for Impact, 2015). Furthermore, providing worked examples can help pupils to focus on the relevant parts of the problem rather than wasting time looking at irrelevant solutions, or mismatching problems and solutions (Wittwer & Renkl, 2010). Worked examples provide scaffolding to help pupils master a particular part of the problem, both securing it within their mental model and making it available to draw on when required for the next part of the problem.

In sum, including concrete and abstract examples, and modelling by thinking aloud through worked examples, can effectively support pupils to understand new ideas without overloading their working memory.

Checking pupil understanding

In the opening problem, Ms Thomas also wanted to ensure that her pupils understood content. While examples and modelling can convey material, she will only know whether pupils have understood by checking their understanding. Pupils tend to believe that they understand something if it feels familiar, even if their understanding is superficial (Christodoulou, 2016). Formative assessments can help Ms Thomas gather information about what each of her pupils does and does not understand. After modelling how to complete a problem and before getting pupils to practise independently, Ms Thomas could ask questions to check pupil understanding.

Nuances and caveats

While guided instruction through modelling is more effective for novices than other forms of instruction, removing cognitive supports as pupils gain expertise is vital. Where pupils already have a strong understanding of how to solve a problem, worked examples may distract them from a process which they are capable of completing independently (Pashler et al., 2007).

Key takeaways

Ms Thomas’s expositions will better match pupil needs if she understands:

  • The importance of preventing pupil overload by first building on prior knowledge.
  • The ‘I-We-You’ approach helps her to ensure she manages pupil thinking and working memory effectively.
  • Using concrete and abstract examples, modelling, and worked examples in expositions supports pupils when introducing new concepts and processes.
  • Checking pupil understanding prior to letting them practise independently can be a powerful approach.

Further reading

Deans for Impact (2015). The Science of Learning.


Deans for Impact (2015). The Science of Learning.

Lemov, D. (2015). Teach Like a Champion 2.0. Jossey-Bass, 2nd Edition.

Pashler, H., Bain, P. M., Bottge, B. A., Graesser, A., Koedinger, K., McDaniel, M., & Metcalfe, J. (2007). Organizing Instruction and Study to Improve Student Learning. US Department of Education.

Rosenshine, B. (2012). Principles of Instruction: Research-based strategies that all teachers should know. American Educator, 36(1), 12–20.

Sweller, J. (2016). Working Memory, Long-term Memory, and Instructional Design. Journal of Applied Research in Memory and Cognition, 5(4), 360–367.

Wittwer, J., & Renkl, A. (2010). How Effective are Instructional Explanations in Example-Based Learning? A Meta-Analytic Review. Educational Psychology Review, 22(4), 393–409.


Answer the questions in the quiz to check your understanding of the evidence summary.

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Reminder of key takeaways

Ms Thomas’s expositions will better match pupil needs if she understands:

  • The importance of preventing pupil overload by first building on prior knowledge.
  • The ‘I-We-You’ approach helps her to ensure she manages pupil thinking and working memory effectively.
  • Using concrete and abstract examples, modelling, and worked examples in expositions support pupils when introducing new concepts and processes.
  • Checking pupil understanding prior to letting them practise independently can be a powerful approach.

Reflect on the following questions

  1. What did you see in this module that you already do or have seen in other classrooms?
  2. What do you feel is the gap between your current practice and what you have seen in this module?
  3. Which of the ‘key takeaways’ do you need to focus on? Where and when might you try to apply them to your teaching?