Infographic: The Math Error Behind 30 Years of Education Policy

An influential study's failure to consider factors like poverty, race, and immigration concealed the fact that scores were improving.

The push to reform America’s failing schools dates to the Reagan administration’s 1983 report, “A Nation at Risk,” which found that U.S. students’ test scores were plummeting. That news was so startling that Reagan’s energy secretary, Admiral James Watkins, commissioned the Sandia National Laboratory to find out why. What Sandia found (in a report not published until 1993) was even more startling: Although the overall average score had gone down, scores had gone up in each demographic group. How’s that work?

Across the board, scores had gone up.

For starters, it’s established that less-advantaged children, whether poorer, or members of a disfavored minority, or recent immigrants, score lower on standardized tests.

In the period of time covered by “A Nation at Risk,” the number of disadvantaged students had increased much faster than the number of more advantaged ones. During that time, scores for each group had gone up. Schools and teachers were succeeding.

Here’s an illustration of how the math works:

1,000 students take a standardized test. They are evenly split among income groups, and the richer students score better than the poorer ones. Later, 1,000 students take the same test. In between, the demographics have shifted. Across the board, scores have gone up. But because there are so many more low-income students than there used to be, the overall average goes down. This is exactly what the Sandia report said had happened in the United States.

“A Nation at Risk” didn’t prove that schools were failing. It proved that the study’s authors failed math.