Much of the impetus for new teacher evaluation systems has been based upon the belief that teaching experience is less important than demonstrating competence via student test scores. This belief has become popular among corporate reformers for providing a potential mechanism to remove older more expensive teachers and replace them with cheaper less experienced teachers.
We have published hundreds of articles and studies here at Join the Future pointing out the dangers of relying upon student test scores for the purposes of evaluating teacher quality. Study after study has found the measures to be unreliable and unfair. Worse, it exploded that amount of testing students are having to needlessly endure, and sapped the morale of educators dealing with an unfair system to the point where an exodus of talented educators form the profession is real and happening.
Now comes evidence that the premise itself, that experience doesn't add to quality over time, is fatally flawed.
The evidence comes in the form of 2 new studies. The first in a paper published by Harvard, titled Productivity Returns to Experience in the Teacher Labor Market: Methodological Challenges and New Evidence on Long-Term Career Improvement, the researchers conclude
We find consistent evidence across models that teachers improve most rapidly during their first several years on the job but also continue to improve their ability to raise student test scores beyond the first five years of their careers. This directly contradicts the standard policy conclusion that teachers do not improve after the first three to five years of their career. Finally, we find suggestive evidence across multiple modeling approaches that teachers continue to improve even later in their careers, particularly in mathematics.
The second in a working paper, published by the National Center for Analysis of Longitudinal Data in Education Research (CALDER), titled RETURNS TO TEACHER EXPERIENCE: STUDENT ACHIEVEMENT AND MOTIVATION IN MIDDLE SCHOOL, the author finds
We use rich longitudinally matched administrative data on students and teachers in North Carolina to examine the patterns of differential effectiveness by teachers’ years of experience. The paper contributes to the literature by focusing on middle school teachers and by extending the analysis to student outcomes beyond test scores. Once we control statistically for the quality of individual teachers by the use of teacher fixed effects, we find large returns to experience for middle school teachers in the form both of higher test scores and improvements in student behavior, with the clearest behavioral effects emerging for reductions in student absenteeism. Moreover these returns extend well beyond the first few years of teaching. The paper contributes to policy debates by documenting that teachers can and do learn on the job.
These findings should come as no surprise. The claims that experience don't count beyond the first few years was always a spurious argument, running counter to most people's own working life experience and observations.
It is past time to discard corporate education policies designed to cheapen public education, and instead embrace quality through team working, professionalization, and ongoing career training