Adjusting the testing gap


In the July 25, 2006 Wall Street Journal, Charles Murray has a commentary titled “Acid Tests” which describes how the way that the No Child Left Behind program uses test scores is misleading.

By adjusting what states use to measure “proficiency,” states can appear to be closing the gap between different groups of students. In Texas, the gap between the percentage of white and black students that passed a test was at one time 35 percentage points. Now it is only ten. Does that mean the gap in true student learning and performance has decreased?

The answer is we can’t tell from the data we have. Perhaps Texas made the test easier, or changed the definition of passing, or “taught to the test.” Any of these could explain the narrowing of the gap. As Mr. Murray wrote: “If there really was closure of the gap, all that Texas has to do is release the group means, as well as information about the black and white distributions of scores, and it will easy to measure it.”

The fact is that these tests, administered by the individual states, are subject to manipulation that is not in the best interests of schoolchildren:

Question: Doesn’t this mean that the same set of scores could be made to show a rising or falling group difference just by changing the definition of a passing score? Answer: Yes.

At stake is not some arcane statistical nuance. The federal government is doling out rewards and penalties to school systems across the country based on changes in pass percentages. It is an uninformative measure for many reasons, but when it comes to measuring one of the central outcomes sought by No Child Left Behind, the closure of the achievement gap that separates poor students from rich, Latino from white, and black from white, the measure is beyond uninformative. It is deceptive.

You can learn more about deceptive testing from a recent study performed by The Civil Rights Project at Harvard University. A press release titled “Testing the NCLB: Study shows that NCLB hasn’t significantly impacted national achievement scores or narrowed the racial gaps” is at


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