방법 비교

	NASA-TLX	사고 구술법 (Think-Aloud Protocol)
분야	인간-컴퓨터 상호작용	인간-컴퓨터 상호작용
계열	Hypothesis test	Hypothesis test
기원 연도	1988	1980
창시자	Sandra Hart and Lowell Staveland	K. Anders Ericsson and Herbert A. Simon, adapted to HCI by Clayton Lewis
유형	Multi-dimensional post-task questionnaire for measuring subjective mental workload	Protocol for capturing user cognition and decision-making during task execution
원전	Hart, S. G., & Staveland, L. E. (1988). Development of NASA-TLX (Task Load Index): Results of empirical and theoretical research. In P. A. Hancock & N. Meshkati (Eds.), Human Mental Workload (pp. 139–183). Elsevier.	Ericsson, K. A., & Simon, H. A. (1980). Verbal reports as data. Psychological Review, 87(3), 215–251.
별칭	Task Load Index, TLX, NASA-TLX	Talk-Aloud Protocol, Concurrent Thinking Aloud, TA
관련	4	4
요약	The NASA Task Load Index (TLX) is a multi-dimensional subjective workload assessment tool developed at NASA Ames Research Center by Sandra Hart and Lowell Staveland in the 1980s. TLX measures perceived mental workload across six dimensions—mental demand, physical demand, temporal demand, performance, effort, and frustration—allowing researchers and practitioners to understand the cognitive and affective burden of tasks and interfaces. The instrument is widely used in human factors, cognitive engineering, and HCI to identify task bottlenecks and evaluate system designs.	The Think-Aloud Protocol is a usability testing method in which participants verbalize their thoughts while completing tasks on a system. As users navigate an interface, they continuously narrate their observations, interpretations, and reasoning, allowing researchers to understand their mental models, decision-making, and frustration points. Originating from cognitive psychology research by Ericsson and Simon (1980), this method was adapted for HCI by Clayton Lewis and has become one of the most widely used techniques for identifying usability problems and understanding user behavior.