Research School Network: Effective Explanations Simple ways to reduce the cognitive load of teacher explanations


Effective Explanations

Simple ways to reduce the cognitive load of teacher explanations

by Durrington Research School
on the

Teacher explanations are a vital part of education. As a profession we now have a greater appreciation for the role cognitive load can play in our students learning experience. Sometimes great explanations can be unravelled by poor management of our student’s cognitive load.

Today I want to suggest some simple things we can do to ensure our explanations are cognisant to our students working memory capacities.

1. Control the flow of information.

We all know that chunking is a great way of ensuring students have time to process the information we provide. We can sometimes get caught up in our own passion for our topic and forget to chunk our explanations.
The simplest way of ensuring the explanation is chunked is by starting with a blank canvas. Planning to live draw can feel daunting at first, but with practice and planning it is the perfect way of directing attention to the most relevant information and avoiding distractions. If you prefer PowerPoints to a visualiser then considering carefully what information appears on each slide is vital. The judicious use of relevant images and text spread over multiple slides is an effective tool. As is using animations to highlight or add relevant information in sequence.

2. Activating prior knowledge.

Students can only learn new information by building on their existing knowledge, or schema. Before starting an explanation spend time assessing and activating the relevant prior knowledge of the class and adapt your explanation accordingly. A simple mini whiteboard quiz can get the job done in a few minutes and gives you vital clues about what areas might need a more detail.

3. Dual coding.

The working memory model identifies the paths that visual and sound information follow to be different. By enhancing verbal explanations with relevant images, we can expand a students working memory capacity. This is the crux of effective dual coding. Dual coding often gets conflated with the use iconographic illustrations. While these can be used effectively as dual coding these are not the only way. Simple drawings, well chosen photos and diagrams can effectively dual code information. Dual coding is a concept that is often thought to be more complicated than it really is. Just follow this simple rule: Ensure each image adds to the explanation. If it is aesthetic, then get rid of it.

4. Narrative structures and seductive details.

Daniel Willingham has written about the way the human mind appears to treat stories with a certain amount of privilege. Narrative structures that have characters conflict and consequence seem to be easier to remember than just abstract facts. Teachers should use narrative structures carefully though. Sometimes extra information can distract students from the main points of the story. These are known as seductive details and diminish the explanations effectiveness. When planning a narrative structure to an explanation try to only include extra information that helps to illustrate a difference or similarity between the characters involved and try to avoid just random trivia.

5. Creating the environment.

When explaining something we need students’ attention. If they do not attend to the relevant information, then they have no chance of learning it. We need to ensure all students can give the teacher their attention by creating a calm and silent environment. As teachers we need to tell the students where to look to get the most relevant information and we need to do our best to ensure other students are not distracting them. We need to modulate our voice to emphasise key features and pause to ensure students are paying attention when needed.

6. Questioning.

Questions are used to check students understanding but also to ensure all students are paying attention. For example, Cold Call does a brilliant job of keeping all students engaged in the lesson. When giving explanations it is vital, we used sporadic questions to check students are paying attention. This is a double-edged sword as too many questions will disrupt the narrative flow, so it is best to just drop a single question in when there is a natural break in the explanation, but this is very context-specific so you might want to experiment.

Adam Robbins


Further reading.


Teaching secondary science: A complete guide by Adam Boxer has an excellent theoretical model for building explanations that is relevant to most subjects

Cognitive load theory: Research that teachers need to understand by NSW government is a great overall guide to the practical implications of cognitive load theory.

The evolution of a presentation is a blog I wrote during lockdown that illustrates simple ways of adjusting PowerPoints to direct attention

The privileged status of stories is an article by Daniel T Willingham about narrative structures and the mind

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