* A students know that they are A or B students;
* B students know that they are B students;
* the top C students know that they are C students;
* the bottom C students and the D students "know" that they are A students.
This didn't sit right with me when I first read it, based on personal experience. In the school system I went through, people got segregated into ability groups and, as far as I could recall, those placed in the bottom group usually agreed that they were the worst performers at this subject. Maybe I thought this had something to do with the psychological effect being classified as 'the bottom group', and couldn't think of much intelligent to say, so didn't.
But I just came across a
blog post on Citation Needed today, which points out that Dunning and Kruger's experiments are often misinterpreted. The relevant bit is in this graph from the original paper:
The worst performers still tended to consider themselves the worst performers, they just grossly underestimated how much worse they were. Your point above would be better if it finished "the bottom C students and the D students "know" that they are top C students, as do those who have no hope of getting a D."
Edited by caffeine, : To add link - thank RAZD