방법 비교

	인터페이스 사용성 척도(IUM)	운영자 수행 평가 척도 (OPAS)
분야	인간공학	인간공학
계열	Process / pipeline	Process / pipeline
기원 연도	1986	1993
창시자	John Brooke, James R. Lewis	William W. Wierwille, Frank T. Eggemeier
유형	Self-report	Observer-rated / Self-rated
원전	Brooke, J. (1986). System Usability Scale (SUS): A quick and dirty usability scale. In B. Weerdmeester & M. Evaluating the Usability of Human-Computer Interfaces (pp. 5-7). IOS Press.	Wierwille, W. W., & Eggemeier, F. T. (1993). Recommendations for mental workload measurement in a test and evaluation environment. Human Factors, 35(2), 263–281.
별칭	IUM, Usability Assessment, System Usability Scale	OPAS, Performance Rating Scale
관련	4	4
요약	Interface Usability Measure (IUM), exemplified by the System Usability Scale (SUS) developed by John Brooke in 1986 and extended by Lewis and others, is a rapid, single-scale or multi-item assessment of perceived interface usability. IUM captures how easy, intuitive, and satisfying users find an interactive system, ranging from 10-item SUS questionnaires to custom domain-specific usability measures. IUM is widely used in software development, web design, and human-factors research to quantify user perception of system ease-of-use and guide iterative interface improvement.	The Operator Performance Assessment Scale (OPAS), formalized by Wierwille and Eggemeier in 1993, is a structured rating method for assessing operator task performance on multiple dimensions (primary task accuracy, secondary task accuracy, task completion time, error rate, procedure adherence) in applied settings. OPAS bridges subjective workload perception (NASA-TLX, situational awareness) and objective behavioral metrics by capturing expert judgment of performance quality across multiple performance channels, enabling holistic evaluation of how well operators managed task demands.