As above, an interesting article on evaluations in the JPE: "Does Professor Quality Matter? Evidence from Random Assignment of Students to Professors,"
https://www.jstor.org/stable/10.1086/653808 . Here's a key part of the introduction: "Student evaluations are positively correlated with contemporaneous professor value-added and negatively correlated with follow-on student achievement. That is, students appear to reward higher grades in the introductory course but punish professors who increase deep learning (introductory course professor value-added in follow-on courses)."
more beeching by crummy teachers.
try a bit harder ok?