English tests? Check. Math tests? Check. Summer vacation? Not so fast. Students in New York State sweated their way through some of the toughest exams in state history this spring, The New York Times reports. Now hundreds of thousands of them will receive a reward only a stonyhearted statistician could appreciate: another round of exams. As school districts across the country rush to draw up tests and lesson plans that conform to more rigorous standards, they are flocking to field tests — exams that exist solely to help testing companies fine-tune future questions…