Cognitive load theory

In one line: Working memory can only juggle a few things at once — overload it and learning breaks down.

Cognitive load theory is a cognitive-approach term. Working memory holds only a handful of items at once, so how we present information decides whether it can be processed.

Think of working memory as a small desk. A few items fit and can be worked on; pile on too much and things fall off. This links to the concept of measurement: the theory is built on the measurable limits of memory capacity.

Memory hook: Small desk, limited space. Overload working memory and nothing gets learned.

Key idea: Total load comes from three sources — some unavoidable, some wasteful, some useful.

Take a student learning to solve equations. The intrinsic load is the maths itself; a cramped, cluttered worksheet adds extraneous load; and clear worked examples free up capacity for germane load — actually understanding the method. Good teaching cuts the wasteful load.

Go further — higher-level insight: You can't add capacity, only manage it. Since working memory is fixed, the practical goal is to cut extraneous load and match intrinsic load to the learner — so more capacity is left for the germane load that actually builds learning.

Key idea: The theory is practically powerful in education, but the three loads are hard to measure separately.

So cognitive load theory is a highly useful, evidence-based guide to designing learning, but a strong evaluation notes that the loads are hard to measure directly and vary between people, so it is easier to apply than to test precisely.

Watch out: More effort isn't always better. Making a task harder can overload working memory and block learning — the aim is the right load, not maximum load.