NCPA - National Center for Policy Analysis

Credentials Unrelated to Student Achievement

September 19, 2011

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: certification, advanced degrees and years of experience in the classroom.  Little to no relationship exists between these credentials and the gains that a teacher's students make on standardized math and reading exams.  Furthermore, external teacher credentials tell us next to nothing about how well a teacher will perform in the classroom.  A new method of identifying the best teachers is needed -- one that focuses on measuring the contributions that teachers actually make in the classroom, says Marcus Winters, a senior fellow at the Manhattan Institute.

Winters, along with Jay Greene and Bruce Dixon, utilized a data set provided by the Florida Department of Education to study the relationship between elementary school teachers' training and experience, on the one hand, and the learning gains made by their students in a given year, on the other.

  • No relationship was found between a teacher's earning a master's degree, certification or years of experience and the teacher's classroom performance as measured by student test scores.
  • Even very detailed information about the teacher's preparation in college said very little about how effective that teacher would be in the classroom.

In addition, not a single one of the 34 studies that used a "high-quality" methodology (i.e., methodology that accounted for previous student test scores) evaluated in a recent review of the research by Eric Hanushek and Steven Rivkin found a relationship between a teacher earning a master's degree and student achievement.

Over the last two decades, we have learned two important lessons about public school teachers: teacher quality varies dramatically; and almost nothing we know about a teacher before he or she enters the classroom accurately predicts how successful that teacher will be.  Now heavily documented through empirical research, these findings should point us toward a fundamental transformation of our system for evaluating public school teachers, says Winters.

Source: Marcus Winters, "Measuring Teacher Effectiveness: Credentials Unrelated to Student Achievement," Manhattan Institute, September 2011.

For text:


Browse more articles on Education Issues