Multimillionaire equity investor Rex Sinquefeld doesn’t like public education. Apparently he doesn’t like teachers either. He doesn’t think teachers should be evaluated by their administrators but by the standardized test scores of their students. Evidently he doesn’t know that this method of evaluating teachers has failed to work wherever it was tried; evidently he doesn’t know that even the District of Columbia, which was first to implement this method, has put it on hold. Mr. Sinquefeld also seems unaware that about 70% of teachers don’t teach tested subjects.

He was unable to get these ideas adopted by the Missouri state legislature so he created a Constitutional amendment, which will be on the ballot this fall. It is called Constitutional Amendment 3.

If it passes, the problems and costs will begin. Missouri will have to develop tests for every subject that is taught and administer them at the beginning and end of each course. How will Missouri measure the effectiveness of art teachers, music teachers, physical education teachers? Vast new sums must be spent to create and administer dozens of new tests.

Experience in other states shows that teachers in affluent districts will get higher ratings than those who teach children in poor districts and those with disabilities. The tests measure advantage and disadvantage, not teacher quality.

The bottom line with Mr. Sinquefeld’s proposal is that it will be very costly and it will not identify the best and worst teachers. It will reward teachers in high-income districts and punish those who choose to work with students who are English learners or have disabilities or are homeless.

It will take decision-making power away from local administrators and shift it to a centralized bureaucracy. It has been tried and failed in many districts. It demoralizes teachers by reducing their jobs to nothing more than test scores.

There are research-proven ways to improve education, such as early childhood education, reduced class sizes for the students who need extra help, regular access to medical services for those who can’t afford it, and experienced teachers. These strategies have a solid research base.

Missouri should do what works, rather than investing many millions of dollars in proven failure.