I'm skeptical of this psychology research into teaching evaluation ratings. It also doesn't help that this article doesn't elaborate on the general methodology of that research. I think that having a correlation between racial minority/female and lower teaching outcome offers limited insight. It would be more meaningful if the study had an auditor to evaluate the instructor against the students average ratings. In particular, instructors of color who have a thick accent or struggle to speak clearly shouldn't be included in the study for bias as their ratings would be lower because of their poor communication skills. In my own experience as an engineering student, I strongly question the role of bias in a student's perception simply because the material is so hard that most could care less what the instructor looks like. Professors who can effectively explain difficult concepts clearly, are highly respected and valued by students. Speaking of bias, couldn't research be biased?