I used to work in a school with a five-star rating and commenting system. The difference was that the students wrote their comments in their local language, in the part of the site intended for students. Many of them thought of this as of anonymous rating, something their teachers cannot see or understand. The problem was there were a lot of simply wrong comments and ratings (I was lucky enough, though, some other teachers suffered a lot), stemming from either misunderstanding or malice from the people not courageous enough to molest other people while looking them in the eye. Also, different people have different personalities and and cultures they originate from, e.g. some will confuse advice with an insult, some respond poorly to criticism no matter how encouraging you are, some expect you to be a clown, not a teacher, and so on. I am very flexible so I got one bad comment out of hundreds, but some of my coleagues were not nearly that lucky, although they are outstanding in what they do. Malice cannot be remedied, some people are simply mean - or even so selfish that they want to reduce a teacher's rating so they can book them more easily (I got multiple confessions). However, you can and should tell your teacher what you think of their class directly. If you ever book my class, do tell me if anything is wrong or could be better, I want to know. I also want to know you better, and your needs and preferences, so I can prepare better. I am new to this site, so I can't comment further on the rating system. Looking forward to meeting some of you, either in class or in comments and messages. So far I am very happy with the people here! Cheers.