Idiosyncrasies and Discrepancies in States' Implementation of NCLB

The No Child Left Behind (NLCB) Act required states to adopt
accountability systems measuring student proficiency on state
administered exams. Based on student test score performance in 2002,
states developed initial proficiency rate targets and future annual
benchmarks designed to lead students to 100% proficiency on state
exams by 2014.

Any year a school fails to meet these targets, either
across all students or by various subgroups of students, the school
does not make Adequate Yearly Progress. While the federal
government's legislation provided a framework for NCLB
implementation, it also gave states flexibility in their
interpretation of many NCLB components, and school failure rates
ranged from less than 1% to more than 80% across states.

This paper explores how states' NCLB implementation decisions affected
their schools' failure rates. Wide cross-state variation in failure
rates resulted from how states' decisions (e.g., confidence intervals
applied to proficiency rates, numerical thresholds for a student
subgroup to be held accountable) interacted with each other and with
school characteristics like enrollment size, grade span, and ethnic
diversity. Subtle differences in policy implementation led to
dramatic differences in measured outcomes.