NEA president Dennis Van Roekel has made this argument:
"Under the No Child Left Behind law, states have released test results that supposedly tell us how many students are proficient in math and reading. The problem is, each state sets its own benchmark for proficiency, and different students are held to different standards.
Imagine if the batting average of one baseball player was based on at-bats against Cy Young winners, while another average was compiled from plate appearances in the minors. You couldn't tell much by comparing the two numbers."
My response: We already have a test that allows us to compare states: The NAEP. In fact, the evidence for differing standards on state tests comes from comparisons with the NAEP.