The state is one step closer to changing the way teachers are evaluated.

The State Board of Education on Wednesday gave initial approval to a plan that ties teachers' performance more closely to student achievement.

Evaluating educators based on performance is a required part of the state's exemption from the federal No Child Left Behind law. A new evaluation system is being piloted in 49 schools in 13 districts across the state.

The plan presented to the board included a new rating system for teachers with ratings of exemplary, highly effective, proficient, needs improvement and ineffective. The ratings are a departure from an earlier plan that called for ratings of A through F, which drew criticism from teachers and education groups.

Several education groups on Wednesday raised concerns about the new system's focus on student growth. The plan would require that 30 percent of teachers' evaluations be based on students' test scores.

Kathy Maness of the Palmetto State Teachers Association suggested reducing the weight of student growth to 15 percent and adding categories of professionalism and classroom reflection for a weight of 10 percent and 5 percent, respectively.

Bonnie Wilson, who is a principal of an elementary school in Hampton County, said her school is among those piloting the new evaluation system. She said measuring student growth has helped teachers better quantify whether their students are improving, and drive professional development to help teachers improve.

State School Board member Larry Kobrovsky, who represents Charleston and Berkeley counties, said Thursday that the initial approval of the new evaluation system is "in no way indicative of the sentiment on the board of passing the final version."

Kobrovsky said he continues to have concerns about tying student achievement and test scores to teachers' employment. The State Board of Education will take a final vote on the new evaluation system later this year.

Also on Wednesday the board voted against a proposal to allow South Carolina to withdraw from the Smarter Balanced Testing Consortium that is developing tests to meet new federal education requirements known as the Common Core State Standards.

Reach Amanda Kerr at 937-5546 or at Twitter.com/PCAmandaKerr.