This paper presents findings from a scale validation study of discussion engagement using data from multiple in-person courses from a public flagship university in the United States. The Discussion Engagement scale conceptualizes discussion as a collective inquiry that requires an inclusive classroom climate and individual contributions that promote the engagement of others. The scale measures individual behaviors and experiences along four dimensions: skills, confidence, openness within classroom discussions, and perception of an inclusive classroom climate. The methodology included: conceptual development of the construct, expert reviews, cognitive interviews, data collection of the target group, exploratory factor analysis, data collection of the target group using a revised scale, confirmatory factor analysis, and comparison with an existing scale. EFA and CFA find that the scale has a strong factor structure that parallels the theoretical framework. The subscales have strong reliability, as well as evidence of convergent and discriminant validity. The Discussion Engagement scale has potential for measuring student-reported experiences with discussion in university courses. [ABSTRACT FROM AUTHOR]