John Sweller

John Sweller (b. 1946)

Key Contribution / Core Idea

Originator of Cognitive Load Theory (CLT) — how working-memory limitations shape how we should teach.

Background / Context

Australian educational psychologist. Developed CLT from lab studies on problem solving in the 1980s onwards.

Main Theories / Methods

• Working memory has limited capacity; instruction must respect this.

• Use worked examples to reduce unnecessary load.

• Gradually fade support as learners gain expertise (expertise reversal effect).

• Avoid split attention, redundant information, or over-complex visuals.

Relevance to Modern KS3/4 Teaching

Crucial for designing step-by-step explanations in maths and science.
Helps decide when to demonstrate, when to scaffold, and when to let students try independently.

How His Ideas Link to Others

Supports Rosenshine’s sequencing; complements Willingham’s memory research.

Strengths and Appeal

• Backed by decades of cognitive and instructional research.

• Explains why “discovery learning” can overload novices.

Criticisms and Limitations

Less guidance for highly creative or exploratory tasks once students are experts.

Legacy / Lasting Influence

Core component of modern teacher training and the Education Endowment Foundation’s guidance reports.

Further Reading

Sweller, J., Ayres, P., & Kalyuga, S. (2011) Cognitive Load Theory.