Earlier this year U.S. Secretary of Education Arne Duncan issued the warning that 82 percent of schools would fail to make the grade this year under the No Child Left Behind Act in an attempt to encourage Congress to rewrite the law. But a new report from the Center on Education Policy estimates that the real number is closer to 48 percent, writes Michele McNeil at Ed Week.

The proportion of schools that are estimated to have failed to make “adequate yearly progress” (AYP) under NCLB during the 2010-11 school year is up from 39 percent the year before. Duncan’s 82 percent prediction, which was criticized at the time for only serving to create an atmosphere of fear and damage the department’s credibility, appears to be off-base.

Duncan may have originally used this 82 percent figure to try and stimulate Congress into reauthorizing the law. It didn’t work, meaning the Department of Education began issuing waivers from key elements of NCLB.

Duncan commented on the report’s data:

 ”Whether it’s 50 percent, 80 percent, or 100 percent of schools being incorrectly labeled as failing, one thing is clear: No Child Left Behind is broken,” he said. “That’s why we’re moving forward with giving states flexibility from the law in exchange for reforms that drive student success.”

Only three states, plus the District of Columbia, actually hit or exceeded Duncan’s estimate on failure to make adequate yearly progress: the District of Columbia, at 87 percent; Florida; at 89 percent; Missouri, at 88 percent; and New Mexico, at 87 percent.

Interestingly, while states like Wisconsin, Kansas and Rhode Island far surpassed the expectations of schools making the progress, the report shows that it doesn’t necessarily mean they have better K-12 systems.

Instead, the difference in AYP success is likely more a reflection of test difficulty, cut scores, student demographics, and the academic targets, writes McNeil.