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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.