Fact: 3-5% of teachers in the Chicago public schools cheat to boost the performance of their classrooms on standarized tests (reported in this paper).

This is hardly surprising for anyone who passed through the American public school system. I recall how, in sixth grade, the day before we had to take some important state-wide test, my teacher took a copy of the exam -- which of course had arrived in the school a few days before the actual exam date - and went through it with us question by question. She did not reveal the questions themselves or answers; but for each question on the test, she wrote a similar question on the board, perhaps with different numbers if it was a math question, or with a different sentence if it was a verbal one, and showed us how to solve it.

I wonder whether the rate of student cheating in the Chicago public schools is higher than 5%.