Cognitive Load

The amount of mental resources needed to understand and interact with an interface.

Our brains have a limited amount of processing power

When the amount of information coming in exceeds the space we have available in our brain, we struggle to keep up — tasks become more difficult, details are missed, and we begin to feel overwhelmed.

Intrinsic cognitive load

Refers to the effort required by users to carry around information relevant to their goal, absorb new information and keep track of their goals. For example, we can only hold three or four items in our working memory at once.

Extraneous cognitive load

Refers to the mental processing that takes up resources but doesn't help users understand the content of an interface (e.g. distracting or unnecessary design elements).

cognitive-psychologyusability

Origin

Cognitive load theory was developed in the late 1980s by John Sweller out of a problem-solving study. In many ways it was an expansion on the information processing theories of George Miller. Sweller argued that instructional design can be used to reduce cognitive load in learners, culminating in his 1988 publication of "Cognitive Load Theory, Learning Difficulty, and Instructional Design".