Evanston/Skokie School District 65 board candidate J.B. Rees Thursday night challenged the district's evaluation system that now rates 72 percent of teachers "excellent."
Almost all the rest, he said, receive an "average" rating.
Rees, speaking at a candidate forum at Rhodes Magnet School, said that at a meeting last month for school board candidates with Superintendent Hardy Murphy he asked the superintendent whether he could identify the top 50 teachers in the system and was told "'no, the metrics aren't geared that way.'"
"It's pretty tough to tell how well our teachers are doing" if you can't tell which ones are doing the best, Rees said.
He quoted former Microsoft chair Bill Gates as saying that a 5 percent annual turnover rate among teachers would improve the overall quality and morale of teaching staffs.
District 65 has about 1,600 employees, not all of them teachers.
Rees says Murphy told him only "a few" tenured teachers have been let go -- apparently less than five a year.
"If we're unable to move poor performing teachers out of the classroom, we're not going to meet the standards we've set," Rees said, "We're handcuffed."
School Board President Keith Terry argued that the current teacher evaluation system, adopted a couple of years ago, is an improvement over what came before. "Before, 90 percent of teachers were rated excellent," he said.
"Getting rid of tenured teachers is very difficult," Terry added, given provisions in the teachers union contract.
Candidate Richard Rykhus said the district should do more to evaluate which teachers leave and which stay -- and work to make sure that fewer high-rated teacher than low-rated ones depart.
"If we're not retaining the teachers we want, we have to dig to understand why not -- whether it's a lack of professional development opportunities, the school environment or leadership. It could be all sorts of issues," Rykhus said.
Candidate Eileen Buddy said she agreed with Rees that the district should "streamline the process to help lower-performing teachers make a graceful exit."
And incumbent board member Katie Bailey argued the district's new system will make it easier to evaluate teachers.
Also Thursday night, in Washington, D.C. the head of the American Federation of Teachers called for an overhaul of how teachers are evaluated and dismissed.