If school grades make no sense, just wait for teacher evaluations. New Mexico’s school reform plans, A-F school grading and teacher evaluations use a complex statistical formula called Value-Added Modeling, using test scores and other factors. The results are set on a curve defining the “effectiveness” of schools, and soon of teachers.

These plans are intended to inform parents of their school’s or teacher’s quality, and to mandate “remedies” such as possible school closings or firing teachers. School-grading proponents say it is better than No Child Left Behind, which labeled more than 60 percent of our schools as “failing.”

The real problem with NCLB was that it measured schools against an ever-increasing standard of proficiency; 100 percent of students had to be “proficient” by 2015. That would be unattainable even for top scoring schools. But, the A-F system has problems of its own.

I found myself chuckling the other day when a local TV news anchor expressed excitement that “so many of our schools got B’s and C’s.” The new system uses a curve, or “stack ranking,” to categorize schools. Now, instead of being set against a goal, schools are set against each other.

By definition, a curve requires a certain number of schools to fall into each grade category. Although I hate to deflate the enthusiasm of our local news anchor, “so many schools got B’s and C’s” because it was planned that way.

Value-Added Modeling is not about quality, it’s about relativity. If we take the world-class musicians in the National Symphony and rank them on a curve, about 20 percent will be ranked as “failing” or “ineffective.”

Teachers, parents and anyone puzzled by school ratings can attest that there is something wrong with Value-Added Models.

Just Google the term to find overwhelming evidence against using VAM to measure schools. The models typically have a 30 percent to 50 percent margin of error. RAND corporation states, “The research base is currently insufficient to support the use of VAM for high-stakes decisions about individual teachers or schools.”

Despite the evidence, the Public Education Department will also use Value-Added Modeling to score teachers on a curve starting in the 2013 school year.

Not long ago, cardiac surgeons were ranked based on their patients’ survival rate, much as our teachers will be rated on student test scores. The unintended consequences were extremely harmful. Sixty-two percent of those surgeons admitted refusing to treat the sickest patients. When teachers are ranked this way, you can be sure that many will refuse to teach the most challenging students.

Teachers’ names and rankings will be released to the media, which happened in Los Angeles and New York City. News anchors will exclaim, “A full 50 percent of teachers are above average!” They will have us wondering what to do with that “ineffective” group at the bottom.

But parents, students and especially teachers will be scratching their heads, wondering how on Earth they received those scores. We shall be just as bewildered by PED’s rankings then as we are today.

Alyssa Agranat is a National Board Certified Teacher with Albuquerque Public Schools.