The Charleston County School District surprised some longtime teachers last week with a new evaluation system that incorporates student test scores and classroom observations — and their jobs could be at stake.

District leaders say they don't want to fire anyone — particularly not in the midst of a statewide teacher shortage that's only getting worse.

But they say some teachers, including veterans of the profession, have historically gotten a pass from their principals despite producing lackluster results in the classroom. 

Something had to change, said Superintendent Gerrita Postlewait. Some teachers have given all of their students As, even those who failed the End-of-Course tests, she said. Entire schools, including the now-closed Lincoln High, had an unwritten policy of never giving a grade below a 60.

"We do not want to replace teachers," said Postlewait. "We want to improve practice."

Some teachers still see the change as a bad omen. And while parents want good teachers in their children's classrooms, holding those teachers accountable can be a tricky task. Some parents already are concerned that schools "teach to the test," so any added emphasis on standardized tests raises a red flag.

"I think students are taught specifically to the test and not necessarily for education purposes," said Liz Whitworth, a West Ashley mother of two. "They’re not necessarily able to apply what they’ve learned, but they can spit it back out."

School principals called some teachers into their office last week to let them know they would be placed on Professional Growth Plans next school year. While these teachers will keep their existing contracts, the growth plans could be a prelude to firing if the teachers do not improve.

The school district's new evaluation is meant to go above and beyond the state-mandated Assisting, Developing and Evaluating Professional Teaching (ADEPT) system. The district's evaluation includes classroom observations by a team with a school administrator. It also incorporates standardized test scores that show whether students are making academic progress from year to year.

After receiving a barrage of complaints from teachers over the weekend, the district sent out a memo Monday on what it called "data-informed decisions." It said the new system would include data from the Education Value-Added Assessment System, which measures student progress on tests, including SC READY, SCPASS and End-of-Course tests, depending on grade level and subject.

The district previously tried to use such tests under its now-defunct Bridge program, which aimed to improve teacher retention by offering small bonuses at certain schools based on students' improving scores.

The Bridge program didn't go over well with teachers, many of whom were wary of tying any of their pay to fluctuating student performance. It also didn't work. After three years of a pilot program that racked up about $23 million in administrative costs, teacher turnover actually increased at most of the schools. The school board killed the Bridge program last year.

Patrick Hayes, a fifth-grade teacher at Drayton Hall Elementary whose advocacy group EdFirstSC led the charge against Bridge, said teachers around the district were surprised last week when principals called them in for unscheduled meetings.

He said some principals indicated that the evaluations were based solely on test scores and that the school board wanted to fire them — both claims that School Board Chair Kate Darby vehemently denied on Tuesday.

"Our goal is not in any way to fire a bunch of teachers. There aren't enough teachers out there," Darby said.

Hayes said the memo put some of his fears to rest, but that the district should have communicated earlier and more clearly with its employees.

"There was no preparation," Hayes said. "Nobody knew what was comin."

Charleston Teacher Alliance Director Jody Stallings, a Moultrie Middle School English teacher, said the memo still left questions in his mind, namely: How big of a role will student test scores play in evaluations?

Stallings noted a 2010 Economic Policy Institute study raised serious doubts about the usefulness of value-added measures in teacher evaluations, and a similar evaluation plan in New York state schools went up in flames last year after a judge called one teacher's evaluation "arbitrary and capricious."

Postlewait said she should have done a better job communicating with teachers about the plan. She also acknowledged that the data sets are imperfect, adding that test and observation scores are only the beginning of a conversation between principals and teachers.

Postlewait said she expected resistance to a new plan, but she hoped even veteran teachers would take the improvement plan as a chance to reflect and grow.

"I underestimated the intensity of the culture shock and the amount of communication effort I might have made months ago," Postlewait said. "That's my improvement plan. That's my place to reflect."

Reach Paul Bowers at 843-937-5546 or twitter.com/paul_bowers.