Given the challenges facing American public education today, identifying effective teachers is a more vital task than ever before.
Unfortunately, the current system does a poor job at identifying the effective and ineffective teachers. That system needs to be changed.
In the U.S. public school system today, the method used to determine teacher effectiveness — and thus to drive salary, promotion and tenure decisions — is based on a few external credentials.
Those are chiefly certification, advanced degrees and years of experience in the classroom. Public schools don’t consider any measure of how well a teacher actually performs in the classroom.
In a new study to be published in the peer-reviewed journal "Economics and Education Review," my co-authors and I measure the relationship between such credentials and a teacher’s effectiveness.
Essentially, our data matched public school elementary students in Florida to their teachers over several years and measured whether a student’s performance improved when he was assigned to a teacher with a particular set of credentials.
We found no relationship between a teacher earning a master’s degree, teaching certification, or years of experience and the teacher’s classroom performance as measured by student test scores.
Not one of the 34 studies that used a "high-quality" methodology (that accounted for prior student test scores) evaluated in a recent review of the research found any relationship between a teacher earning a master’s degree and student achievement.
Most research does in fact find a positive relationship between the number of years teachers spent in the classroom and their influence on student achievement — but the benefit of that experience appears to plateau after the third to fifth year.
By focusing exclusively on such factors, the current system ignores upwards of 97 percent of what makes one teacher more effective than another. The structure of the current system is simply indefensible, given modern research findings.
The findings of our research and other studies suggest that public schools should develop comprehensive evaluation systems that utilize both quantitative (test scores) and qualitative (classroom observation) measures of teacher effectiveness.
The results of these evaluations should be used to determine which teachers are kept in the classroom, how much a teacher is paid, and whether the teacher receives job protections in the form of tenure.
Over the past two decades, we have learned two important lessons about public school teachers: first, teacher quality varies dramatically, and second, almost nothing we know about teachers before they enter the classroom accurately predicts how successful they will be.
Marcus Winters is a senior fellow with the Manhattan Institute.