In this chapter, potential biasing factors in student evaluations of professors are examined. Because white male professors are the norm, faculty members who are female or who are from other racial/ethnic groups appear to be held to a higher or double standard of performance, Professor attractiveness ratings and age also affect student ratings, as do such course variables as expected grade. For example, higher expected grades are positively correlated with evaluations, even more so than actual grades. These findings should make us cautious in using student ratings as an unbiased measure of teaching effectiveness.
Basow, S. A. and J. L. Martin. (2013) "Bias in student evaluations" In M. E. Kite (Ed.), Effective Evaluation of Teaching: A Guide for Faculty and Administrators (pp. 40-9). Society for the Teaching of Psychology. http://teachpsych.org/ebooks/evals2012/index.php