I remember reading about this problem in the book Freakonomics by Steven Levitt. Teachers have been accused of rigging the results of standardized tests so that schools are not penalized for low performance, as legislated by the No Child Left Behind Act
Cheating among teachers has become epidemic in America’s schools, with cases from New York to California, Florida to South Dakota, Tennessee to Maryland. “It’s more prevalent than anyone wants to admit,” says UNC-Chapel Hill professor Gregory Cizek, an expert on cheating in schools. “Teachers are paid to be role models. It sends a really destructive message to kids.”
Many experts say this disgraceful behavior has surged due to the 2001 No Child Left Behind law, which annually tests academic performance and can punish struggling schools that don’t show improvement. Feeling this heat, some teachers resort to showing students test questions in advance or—if you can believe it—changing their answers after the fact.