Greg Ashman's 'Cognitive Load Theory'

Famously, in educational circles, Professor Dylan Wiliam wrote in 2017 that

I’ve come to the conclusion that Sweller’s Cognitive Load Theory is the single most important thing for teachers to know.

The core of the idea is straightforward enough (and immediately makes sense). Greg Ashman’s book Cognitive Load Theory in the Corwin series A Little Guide for Teachers (I’ve previously recommended Bennie Kara’s Diversity in Schools) is a lucid exposition. ‘Ordinary’ classroom teachers really don’t need more than is here: 75 short pages including Ideas for the Classroom, diagrams and reflective activities.

That ‘core’ is explained in the second chapter, ‘Models of the Mind’:

Cognitive load theory assumes that all new biologically secondary knowledge must pass through working memory before entering long-term memory. This means it is subject to the constraints of working memory, If we overload working memory, then little will be learnt.

Chapter 3 goes through what might seem to be a bewildering array of ‘effects’: Goal-Free, Worked Example, Completion Problem, Split-Attention, Redundancy, Modality, Variability, followed in, Chapter 4, the more complex ones. In each case, Ashman explains these briefly and coherently. Most teachers will be drawn to Chapter 6, ‘Bringing Cognitive Load Theory to your Classroom’, which wisely advises careful application of the theory:

We also need to be aware that teaching is a complex task that can easily overwhelm the teacher’s working memory.