Description: Each year more than 3 million high school students take the SAT or ACT, the college entrance exams required by most four-year colleges in the United States. For decades, however, there have been questions about exactly what these tests measure, what role they play in the admissions process and how predictive they are of academic success. The anxiety-provoking exams, and the multibillion-dollar test-prep industry that has grown up around them, have also become lightning rods in the ongoing national debate over equity in educational opportunity.