assessment of the quality of teaching at their universities. This is in turn drives their decisions regarding faculty promotion, pay rates, and termination.
One of the problems with placing such heavy weight on student evaluations in making decisions about faculty employment is that students don't always give valid feedback. Students, like most people, don't always play fair. Students will sometimes give poor scores (not to mention rude comments) in evaluations, not because the scores are warranted, but because they felt the class was too challenging or made them work too hard. When these ratings are included in aggregate, they punish professors who simply teach difficult courses or demand high standards from their students.
Context is very important in using results from student evaluations, especially because research has shown positive correlations between students' expected grades and their evaluation scores. Essentially, student evaluations are important because they provide direct feedback on how students feel about their professors' ability to educate them. However, they do not tell the whole story, must be taken in their rightful context, and need accompaniment to be used as a key metric in faculty assessment.