Many such websites don't really expect that, and present teachers by averages of all grades, unweighted by how articulate the review actually was. I have seen

Many such websites don't really expect that, and present teachers by averages of all grades, unweighted by how articulate the review actually was. I have seen such websites rare last (and publicly shame) very demanding, very good at that level of teaching, socially awkward teachers — in a way so aggressive that can only de described as late-in-life bullying. I was part of a group of students who personally intervened to avoid a suicide.