Summary

No Child Left Behind is a U.S. law passed in 2001 that aims to improve the performance of American public schools by increasing accountability for student performance and increasing funding for education programs.

Intended Positives

The law aimed to improve student performance by increasing accountability for student performance and increasing funding for education programs.
The intention was to find a process in which the federal government would force states to bring all students to a high bar of proficiency.

Known or Announced Negatives

The law has been criticized for focusing too much on standardized test scores, leading to a narrow curriculum that neglects subjects such as art, music, and social studies, and for imposing unrealistic performance targets on schools.

Observed Positives

The law has led to increased funding for education programs and has helped to improve student performance in some areas.
By making schools report results by subgroup, NCLB shined a light on students in poverty, students of color, those receiving special education services, and English language learners. NCLB pushed schools to give struggling students more attention, support, and help.

More students graduated under the law. The graduation rate for students with specific learning disabilities increased from 57 percent in 2002 to 68 percent in 2011.

While it is generally agreed that the Act was a failure, it has brought to light that the real problem isn’t the act itself, but the process by which federal education policy is made. 

Observed Negatives

The Act came with a massive infusion of new federal spending and federal control, but student achievement has been flat and states have left flexibility today than when the law was first passed.
The intention was to find a process in which the federal government would force states to bring all students to a high bar of proficiency; but with the Act states could only have access to Federal funding if the states administered state tests with high standards.
However, because states wanted access to Federal funding the states started lowering the bar and eroding the idea the 'proficiency'. 
The idea of proficiency now has a much lower standard-and thus educational achievement has greatly decreased.