Demographic data were collected from college students and their graduate teaching assistant (GTA) instructors and analyzed for the impact of these characteristics on the students' ratings of teacher communication effectiveness. Data collected from the approximately 1,000 students and 60 GTAs included age, sex, ethnicity, socioeconomic status, home state or region, father's education level, and mother's education level. In addition, students provided data concerning year in school, major and minor, and anticipated grade in the targeted class. Teaching situational data collected from GTAs included subject taught; course level; class size; years of teaching experience, both in general and in the targeted course; and amount and type of teacher training in the subject area as well as speech communication. Students also completed an instrument measuring their opinions of their teachers' organizational stability, instructional adaptability, and interpersonal inflexibility. Canonical correlations performed on the data yielded a number of conclusions, among them that students rated female GTA instructors more heavily in their instructional adaptability and interpersonal inflexibility than they did males, and that female students tended to rate teachers more on those same dimensions. Male instructors were rated more on their organizational stability. (FL)