The idea of students giving official grades to teachers is new in the centuries-old history of education. Today, the technical side of its implementation is usually discussed, while the purposefulness and usefulness are rarely in focus. The article provides a justification for the view that the student survey is a poor measuring instrument and it is used contrary to its intended use. First, it is unclear what exactly it measures, but it does so imprecisely as there are many known factors that are potentially sources of bias. Second, only to a small extent is the survey actually used to improve the quality of teaching. A separate argument was also given for the opinion that student evaluation of classes not only brings little benefit, but also causes some harm.