Student test results increasingly are becoming the basis for grading teachers.

In Ohio and nine other states, at least half of a teacher’s worth is now determined by student test scores. States are using the information to fire teachers or issue bonuses.

It’s a growing trend.

A study released Wednesday by the National Center on Teacher Quality (NCTQ) reports that 41 states, up from 15 in 2009, now require student data in evaluating teachers.

No state places greater significance on student data in evaluating public school teachers than Ohio, where student performance counts for 50 percent of the teacher’s evaluation. The other half comes from classroom observations by supervisors.

Ohio also is among a small group that connects the teacher’s performance back to the college where he or she was trained.

“In Ohio, we are raising the expectations of students and teachers,” said John Charlton, a spokesman for the Ohio Department of Education. “We know we have to do a better job of educating our students and preparing them for college and careers. The goal of the new teacher evaluation system is to advance instruction in the classroom by identifying areas in which educators can improve. If teachers can improve how they teach, then we can increase the quality of education our students receive.”

But with every report, there are shortcomings and criticism.

The NCTQ report, a non-peer reviewed analysis of state policies, is funded by the Bill and Melinda Gates Foundation, a chief funding source for national content standards, which call for even more testing.

In Ohio, while the standards are tough, not all teachers are included.

Thousands of teachers in publicly funded charter schools — often run by for-profit management companies and among the lowest performing schools in the state — are exempt from the strict data-driven standards if the employer did not opt into the federally funded Race to the Top grant program.

“Unlike traditional public schools, charter schools are free to evaluate and compensate their teachers completely according to the results the teacher get[s] in the classroom, for example,” Charlton said.

And the state’s largest teachers union criticized the report as much for its source as it did the findings.

“It applies a one size-fits-all template to the evaluation of teachers based mostly on test scores,” said Michele Prater, spokeswoman for the Ohio Education Association. “The whole report in and of itself is what we’ve come to expect of NCTQ.”

There is a lot at stake for the union: Six states now link teacher pay directly to the evaluations. Ohio has not yet taken that step.

Unions and public school advocacy groups encourage schools to use multiple tests from multiple years to determine if a teacher has made a positive impact on student growth.

In Pennsylvania, entire schools are held accountable. About 15 percent of a teacher’s evaluation draws on building-level data, encouraging collaboration among staff.

Ohio does not incorporate building data in teacher evaluations or utilize multiple assessments to determine student growth, according to NCTQ’s report.

The NCTQ report neglects external factors, focusing solely on what happens in the classroom.

For example, teachers in poorer communities may see lower ratings.

Students in families that earn more than $40,000 annually learn more than twice as much in a year than students in households that survive on less than $30,000 a year, according to analysis of test data reported by the Ohio Department of Education, which gave an A for value added to 80 percent of affluent school districts and only 36 percent of schools in poorer communities.

Students in communities with median annual incomes around $37,000 score about 10 percentage points lower on proficiency tests compared to students from households that boast incomes above $88,000, according to analysis by the Ohio School Boards Association.

The NCTQ report applauds states for giving parents a voice in grading teachers, but does not take into account that home life and parents can also be a significant factor in the child’s performance.

Education historian Diane Ravitch is critical of evaluations that don’t take into account the external factors — and of NCTQ. She served on the Fordham Institute, a national proponent of school choice that created NCTQ, and she also spearheaded student testing initiatives in the George Bush administration.

“I was on the board at the time. [NCTQ’s] purpose was to harass schools of education,” Ravitch said. “NCTQ is not a professional association. It is a political organization.”

The problem with the student data as a foundation for evaluations is that affluent households create enriching environments, where parents read to children, take them to the zoo or library, and provide the basic amenities that nurture learning.

Doug Livingston can be reached at 330-996-3792 or dlivingston@thebeaconjournal.com.