Two studies were conducted to develop a low-inference, behavioral measure of teacher discussion facilitation in the college classroom. In Study 1 (N = 360), a pilot inventory was developed from extant research. In Study 2 (N = 360), confirmatory factor analyses supported the dimensional structure of the pilot inventory and yielded a new, Teacher Discussion Facilitation Instrument. The 25-item instrument consists of five subscales assessing the degree to which teachers "provoke" and "organize" discussions, "affirm" student contributions to discussions, use a variety of "questions" to guide discussions, and "correct" erroneous contributions to classroom discussions. All five dimensions of discussion facilitation are positively associated with student interest and engagement, as well as indirectly predictive of both outcomes through perceptions of instructor understanding.