Cognitive load

The total amount of mental effort required to complete a task, encompassing the processing of information, decision-making, remembering instructions, and managing attention. Cognitive load theory, developed by John Sweller in the 1980s, distinguishes between intrinsic load (inherent task complexity), extraneous load (unnecessary complexity introduced by poor design), and germane load (effort devoted to learning). In accessibility, cognitive load is a critical concern across disability types: people with cognitive impairments, dementia, or learning disabilities may have reduced processing capacity; blind users navigating by screen reader face high cognitive load from serial audio presentation; and older adults using unfamiliar technology must simultaneously manage the interface, the task, and social demands. Reducing extraneous cognitive load — through simpler layouts, consistent navigation, clear language, and fewer simultaneous demands — is a core accessibility strategy.