Charleston County School District wants to slow down the roll out of its controversial new evaluation system for teachers.

The district has submitted a formal request to the U.S. Department of Education to delay implementing its BRIDGE evaluation, which would factor in students' test scores as a measure of teachers' efficacy, by at least one year.

That means all of the district's teachers wouldn't be subject to BRIDGE until the 2016-17 school year, although some teachers would have students' growth included in their evaluations sooner. The district hasn't heard yet whether its request will be granted.

"I am not inclined to move forward with anything district-wide until I have a much better confidence level than I have right now," said Nancy McGinley, superintendent of Charleston County schools. "Right now, I don't feel we have enough information on how this is going to work. We are taking a more cautious and studied approach to this because we want to do this well. We're trying to slow this down so it doesn't result in something that smart, child-centered people cannot support."

District officials have to ask permission to postpone implementing the new system because it received a $23.7 million, five-year federal Teacher Incentive Fund grant to develop and start it. Charleston County was the only district in South Carolina to win the money.

Separate from this grant, South Carolina is moving toward this same kind of evaluation system. As part of an exemption from certain provisions of the federal No Child Left Behind law, the state promised to evaluate all of its educators in part on students' growth. The state also has asked to be able to wait until 2016-17 to use the new system, but at least one lawmaker has filed a bill that would mandate using the new evaluations by next fall.

The uncertainty about what will happen at the state level is one of the reasons the district wants to hold off on using BRIDGE, McGinley said.

"Charleston can't operate independent of the state," she said.

Districts statewide also will being using a new test for students in 2014-15, and that throws another variable into a formula, she said. Students' growth scores would come from two different exams if the district evaluated all core academic subject teachers using BRIDGE in 2014-15 next year; that is what it proposed to do in the grant.

"While they say it's mathematically possible to figure out . we know there is an adjustment period," she said. ""We are not in a position to go out with anything next year across the entire district."

A third rationale to delay was that the district is developing new ways to define good and exemplary work from students, so there might be another way to measure teachers' contributions, she said.

"We are not going to do anything prematurely," she said. "We're not rushing."

In Charleston, the district is piloting the BRIDGE evaluation system in 14 schools this year. Those BRIDGE evaluations will have at least three components: students' growth, classroom observations and teachers' evaluations on the state ADEPT system.

The most controversial of those elements is value added, which is a formula that will compare what a student's test scores would've been for an average teacher compared to his actual teacher.

Three Charleston teacher advocacy groups have said they oppose the new evaluations because they see value added as unreliable and flawed, and they point to research that backs up their position. Still other teachers, primarily led by the nonprofit StudentsFirst, say value added is a good factor to use in gauging teachers' contribution to students' learning.

McGinley is aware of the strong feelings among those who support and are opposed to the BRIDGE evaluation. She gathered 19 of the most vocal supporters and opposition to the new system for a closed-door meeting on Monday, and she spoke with media afterward about it.

She said she appreciated teachers' ideas and was struck by some of the common beliefs they shared. All teachers thought it important to talk about their students' results with their principals, and they felt as if they shouldn't have to invest 15 or 20 years into the profession before reaching the top teaching salary offered by the district.

McGinley said she wants to continue the open dialogue with teachers, and she said she planned to meet with them again.

Teachers who both support and oppose value added said afterward they were appreciative of the chance to meet with McGinley.

Patrick Hayes, a third-grade teacher who leads the statewide education advocacy group EdFirstSC, said he thought it was an authentic conversation and he was grateful to have it. He's encouraged by the district's request to delay implementing BRIDGE, but said he's still concerned about the district being beholden to the requirements of the federal grant.

Teachers talked with McGinley about using value added along with a structured portfolio and self-assessment to evaluate their contribution to students' growth, but the grant requires the use of students' test scores.

Amanda Hobson, a teacher fellow with StudentsFirst, said it was good to hear different teachers' perspectives, but she hoped the district continued moving forward with implementing the grant as is. Value added can be used as a way to measure teachers' contributions, she said.

Reach Diette Courrégé Casey at @Diette on Twitter or (843) 937-5546.