NASA Task Load Index

A widely used subjective workload assessment tool developed by NASA that measures perceived workload across six dimensions: mental demand, physical demand, temporal demand, performance, effort, and frustration. Participants rate each dimension on a scale, providing a multidimensional view of task difficulty. NASA-TLX is commonly used in accessibility research to evaluate whether assistive technologies impose excessive cognitive or physical burden on users, helping designers identify which aspects of an interaction need improvement.