It's not as if data on student ratings are lacking. So, for the record and in case you happen to find yourself on a committee where student ratings come up, here are some facts to throw into the conversation. Students lack the wisdom and experience to evaluate the effectiveness of their current instructors. Those who give instructors low ratings at the end of a course will in future years appreciate those instructors. If professors in your department who know how you teach rated your effectiveness, the results would probably not differ all that much from your student ratings.
Student evaluations are just popularity contests.
Even if student evaluations have some validity, there's no value in the multiple-choice forms used to collect most of them. You've got to interview students and ask open-ended questions for the results to mean anything. In short, the research shows that student evaluations of an instructor provide a reliable, valid assessment of that instructor's teaching effectiveness, especially if they reflect the views of many students in several different course offerings. So, next time someone says that there's no good way to evaluate teaching, quietly mention that one or two thousand research studies on the topic suggest otherwise. You may not change anyone's mind on the spot, but it might raise the discussion to a higher level than it usually occupies.