Many test-based accountability systems, including the No Child Left Behind Act of 2001 (NCLB), place great weight on the numbers of students who score at or above specified proficiency levels in various subjects. Accountability systems based on these metrics often provide incentives for teachers and principals to target children near current…

This year the Center on Education Policy (CEP) analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps…