Clearly, the Mississippi Department of Education can’t be trusted to rate how its own schools are doing. There’s just too much incentive to inflate the academic performance to make officials look good.

That’s evident in the latest problem related to testing. Last year, the state graded schools and school districts on a curve based on how many points they scored on a formula based mainly on test scores and growth in test scores:

Ten percent made As; 26 percent made Bs; 26 percent made Cs; 25 percent made Ds; and 13 percent made Fs.

When MDE applied the same curve this year, the result was fewer A schools. So last week, it convinced its oversight board to change the curve, but with a caveat. If a school or district does worse under the new curve than the old curve, it will be assigned whichever grade is higher — supposedly for this one year only. We’ll see.

Although MDE officials provide a statistical explanation of why a new curve is necessary, the discussion misses the whole point. There shouldn’t be a curve at all because it prevents parents and taxpayers from knowing which districts are truly failing or excelling.

State Superintendent Carey Wright has proven adept at manipulating the numbers to make things appear rosier than they are. For example, she has repeatedly touted improved graduation rates statewide while leaving out a pertinent fact: The state dropped the objective requirement that students pass certain subject-area tests to graduate.

The Legislature needs to step in and set an objective standard for school ratings rather than letting the education people do it.

— The Greenwood Commonwealth