방법 비교

	상호작용 동등성	사고 구술법 (Think-Aloud Protocol)
분야	인간-컴퓨터 상호작용	인간-컴퓨터 상호작용
계열	Hypothesis test	Hypothesis test
기원 연도	2013	1980
창시자	Shari Trewin, IBM Research	K. Anders Ericsson and Herbert A. Simon, adapted to HCI by Clayton Lewis
유형	Evaluation method validating functional equivalency across alternative interaction modalities	Protocol for capturing user cognition and decision-making during task execution
원전	Trewin, S. (2013). The Interaction Equivalency Principle in assistive technology and universal design. In Universal Access in Human-Computer Interaction (pp. 535–544). Springer.	Ericsson, K. A., & Simon, H. A. (1980). Verbal reports as data. Psychological Review, 87(3), 215–251.
별칭	Equivalent Interaction Design, Alternative Input Validation	Talk-Aloud Protocol, Concurrent Thinking Aloud, TA
관련	3	4
요약	Interaction Equivalency is an evaluation method for validating that alternative input and output modalities (voice, gesture, eye tracking, switch control) provide functionally equivalent access to system capabilities compared to standard input (keyboard, mouse). Developed by Shari Trewin, this method ensures that assistive and alternative interaction methods do not create barriers or diminish user capability. Rather than retrofitting accessibility as an afterthought, Interaction Equivalency assesses multi-modal design at design time, ensuring users with disabilities can access all functionality with comparable efficiency.	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.