Remember the town where all students are above average? A similar exercise in wishful thinking is occurring in the states.

"Far greater shares of students are proficient on state reading and mathematics tests than on the National Assessment of Educational Progress, and those gaps have grown to unprecedented levels since the No Child Left Behind Act became law in 2002," writes Lynn Olson, in Education Week (link for subscribers).

A research center at the University of California, Berkeley, looked at the percentage of students who are "proficient" on both state tests and on the NAEP, commonly known as the "Nation's Report Card."

The NAEP is a standard test given to a sample of students in each state, but states also administer tests to all students within their government-run schools. What researchers found is that there is sometimes a dramatic difference in what the two different assessments show.

Back to Olson's summary: The researchers compiled state and federal testing results for the period 1992 to 2006 from 12 states: Arkansas, California, Illinois, Iowa, Kentucky, Massachusetts, Nebraska, New Jersey, North Carolina, Oklahoma, Texas, and Washington.

In all but two states--Arkansas and Massachusetts--the disparity between the share of students proficient on state reading tests and on NAEP ... grew or remained the same from 2002 to 2006. A similar widening occurred between state and federal gauges of math performance in eight of 12 states.

There's a temptation, all around, to blame No Child Left Behind (NCLB), a law that requires "100 percent proficiency" in the 2013-2014 school year. And certainly, there are problems with the law.

But a more fundamental problem is that NCLB is challenging the interests of the education establishment, a politically powerful interest group that would be significantly disrupted should some of the provisions of the law. The provisions are based on how many and what kinds of students fall into various categories based on state assessments. As Olson points out some people are starting to worry that states will "lower the bar for passing state tests or otherwise adjust their definition of 'proficiency' downward in order to avoid identifying too many schools as missing their targets."

That's a well-founded concern.