Another study indicates that student evaluations tend to be biased against female instructors. You can get the details from Colleen Flaherty, in Slate. The article first appeared in Inside Higher Ed.
It's a new examination that concerns universities in the U.S. and France, building upon prior widely reported research. Interestingly, according to the study, female students tend to rate male teachers higher than they do female teachers, with male students displaying less bias, at least in some categories.
The researchers argue that student evaluations should not be used in hiring decisions, and they anticipate legal challenges in cases where such instruments are an important factor.
For community colleges, this news is especially problematic. While universities evaluate faculty heavily in non-teaching activities such as research and grant production, two-year schools exist mainly for instruction. It's what we do. Therefore, to the degree that student evaluations are the prime measurement of instructional effectiveness, it's a big problem if the process is faulty. However, as the article points out, the biases are not in the evaluations, but in the students themselves. This situation can't be tweaked for better measurement.
One might speculate that community college students may display more prejudice than university students, since first-generation students have received less exposure to higher education as they grew up. It may resemble the difficulty, in prior decades, of female physicians in attracting patients—a cultural bias that presumably is fading.
Another dilemma concerns hiring decisions regarding part-time faculty. With full-timers, supervisors and colleagues get to know each other. Bad teaching practices, such as consistent lateness or absence from class, create chatter on campus that is hard to avoid. However, adjuncts can be less visible on a daily basis, thus making formal student evaluations more significant. This tool may be all a supervisor has to go on.
If these instruments don't measure what they purport to measure, they are invalid by definition. Which means that supervisors should be on the alert for secondary methods to evaluate instruction, such as peer evaluations and class visitations. These techniques are fraught with difficulty also, of course.
It's always tempting to simply declare that student evaluations should not be taken seriously, but if that's the case, why use them? Perhaps it's because they are the best of several bad alternatives. Plus, it would generate controversy if they were eliminated, given the present student-as-customer environment.