The short answer:  Because you can't get our data for free elsewhere; they are patented and exclusive to NeighborhoodScout. Ready for the long answer?

The No Child Left Behind (NCLB) Act was signed into law in January of 2002 in an attempt to quantify student performance across America and identify schools that need improvement. 

Under NCLB, each state receives federal dollars for its public and charter schools based on the performance of their schools. One of the main mechanisms for assessing performance is through testing and test scores. As a result, schools place far more of an emphasis on preparing students for these NCLB standardized tests.

The issue is, that, while the federal government passed down guidelines and standards for the creation of a testing mechanism, the states themselves were left to develop, implement and administer the actual NCLB tests. As a result, there is a wide variation in the difficulty and content of the actual tests that have been implemented from state to state. .

Many websites simply mine the publicly-available No Child Left Behind (NCLB) test scores and display them for free on their websites. But any simple rating system that strictly employs the NCLB results as a basis for comparison is likely skewed due to the widespread differences in the underlying tests. 

NeighborhoodScout's patented school rating methodology accounts for the discrepancies in the tests created by the individual states, and provides a U.S. comparative rating in addition to the in-state rating. So, while a district may boast a high test performance rating compared to other districts within that state, that district could actually be one of the lowest performing school districts in the nation. 

Only on NeighborhoodScout can you find true and nationally-comparable school quality performance ratings.