This is brilliant! (Well, more like a LOLsob). From Amanda Marcotte at Slate:
One of the problems with simply assuming that sexism drives the tendency of students to giving higher ratings to men than women [in students' course evaluations] is that students are evaluating professors as a whole, making it hard to separate the impact of gender from other factors, like teaching style and coursework. But North Carolina researcher Lillian MacNell, along with co-authors Dr. Adam Driscoll and Dr. Andrea Hunt, found a way to blind students to the actual gender of instructors by focusing on online course studies. The researchers took two online course instructors, one male and one female, and gave them two classes to teach. Each professor presented as his or her own gender to one class and the opposite to the other.
The results were astonishing. Students gave professors they thought were male much higher student evaluations across the board than they did professors they thought were female, regardless of what gender the professors actually were. When they told students they were men, both the male and female professors got a bump in ratings. When they told the students they were women, they took a hit in ratings. Because everything else was the same about them, this difference has to be the result of gender bias.