Cognitive Load
Every interface asks for mental effort. Good design spends that effort on the task, not on decoding the screen.
Complex work may be unavoidable. A confusing interface is not.
A setup form asks for twenty fields, explains every rule at the top, and reveals errors only at the end. The task is already demanding. The interface makes it worse by asking people to remember instructions while they work.
Origin
John Sweller developed cognitive load theory through research on learning and problem solving. Its interface value is practical: working memory is limited, so presentation can either support the task or compete with it.
Remove effort that belongs to the interface, such as decoding unfamiliar labels, hunting for status, or remembering information shown on another screen.
Break a complex task into coherent steps, but keep the overall path visible. A sequence helps only when people know where they are and what remains.
Place instructions beside the action they explain. Do not make people memorize a rule from the top of the page and carry it into a later field.
Do not hide essential information in the name of simplicity. The goal is lower unnecessary effort, not fewer words or controls at any cost.
Digital systems
A guided account setup
The flow groups related questions, explains requirements beside each field, and saves progress. People can focus on one decision without losing their place in the larger task.
Physical signals
Airport wayfinding
Signs reveal the next useful decision at each junction. Travelers do not need to memorize the whole terminal map before they can find the next gate.
People spend their limited attention interpreting the product, remembering instructions, and recovering context instead of completing the work they came to do.
Clarify hierarchy, keep needed information visible, use familiar patterns, and divide complexity at points that match the person's decisions.