Most relationships described above remained after taking into consideration various academic and demographic characteristics of instructional faculty and staff. Specifically, after controlling for principal field of teaching, employment status, academic rank, highest degree, gender, race/ethnicity, and age, faculty at 4-year doctoral institutions were still less likely to teach undergraduate classes and to teach such classes exclusively than were their colleagues at 4-year nondoctoral institutions.⁸ In addition, when other faculty characteristics were held constant, full professors were less likely to teach undergraduate classes or teach such classes exclusively than were instructors/lecturers. Faculty with a doctoral or first-professional degree were also less likely to do so than those with only a bachelor's or master's degree.