This post summarizes a paywalled article. Don't bother with the paywall; the summary works fine. The researchers "discovered that students tend to give positive reviews to teachers who are enthusiastic and provide easily digested material that helps them pass the tests; an understandably pragmatic approach." This leads teachers to follow that practise, even if it is not pedagogically effective. "Sadly there is no easy solution to this problem except widening the scope of evaluations to include multiple perspectives and helping students to make more informed evaluations of their learning." Or, if I may add, maybe fixing the incentives students face so they don't priorize 'passing the test'.