South Carolina needs to develop a fair and effective way to evaluate teacher performance in the near future. We agree with critics who say that the new system should entail something more nuanced than handing out letter grades to teachers.

Evaluating educators based on performance is a required part of the state’s exemption from all-or-nothing provisions of the federal No Child Left Behind Law. States can opt out of requirements that all students pass math and reading proficiency tests by 2014, but states instead must come up with a standardized way to evaluate teachers.

State Superintendent of Education Mick Zais said that he’s still exploring evaluation possibilities.

He has stated, however, that he favors a letter grading system because it clearly communicates teachers’ performance.

But the state Association of School Administrators has offered an alternative evaluation plan for teachers and principals that does not include letter grades. As an alternative, it features a four-tiered rating plan ranging from “exemplary” to “unsatisfactory.”

A rating of “unsatisfactory” in any one of five categories would rank a teacher as unsatisfactory overall.

After hearing a presentation from the association, members of the state board of education said unequivocally that letter grades would not be part of the evaluation process. They said that teachers should know that the board is not headed in that direction. ...

That, we think, is an important point. Teachers and principals – who are, after all, state employees – deserve an evaluation that tells them specifically what they are doing right and what they are doing wrong. In most cases, it also should be a constructive evaluation, designed to help teachers and principals improve their performance.

For teachers whose performance is unsatisfactory, the evaluation is likely to be an invitation to find a different vocation. But even then, teachers should know why their performance fell short.