No Child Left Behind is designed to help children, teachers, and schools improve to a higher standard. The law was designed to close the achievement gap between students. The law gives more flexibility in what the schools can do, gives parents more options in how to help their child, and teaching students effectively in a proven way.
More Accountability: Closing Achievement gaps, Accountability of schools
The law requires the states to describe how they will make all students achieve academic proficiency and how they will close the achievement gap between students. (Hoff et. al. 2006)