Association for Public Policy Analysis & Management

There is significant policy focus on the human capital of the nation's STEM teachers. This is motivated by concern over the need to improve STEM outcomes for students in K-12 schools and college and the vast body of empirical evidence showing the importance of teacher quality for student achievement (e.g., Rivkin et al., 2005). One way that states try to ensure a high-quality teacher workforce is by requiring teacher candidates to pass licensure tests, often of both their basic skills and content knowledge, as a requirement for receiving a teaching license. But while several studies (e.g., Clotfelter et al., 2007; Goldhaber, 2007) find modest positive correlations between teacher performance on licensure exams and student math achievement gains in elementary grades, there is little evidence on whether licensure tests provide a useful “signal” of the future quality of secondary STEM teachers.

In this paper we use data from Washington State to investigate whether STEM teacher candidates who score better on licensure tests are also more effective at improving student performance once they enter the teaching workforce. We focus on three subject/grade combinations—middle school (7th-8th grade) math, 9th grade algebra, and 9th grade biology—in which both current and prior year subject-area test scores are available, and estimate value-added models that provide within-subject estimates of the relationship between teacher licensure test scores and student achievement gains. This is the first paper to use traditional value-added methods to investigate the predictive validity of teacher licensure test scores in secondary math classrooms, and the first to consider the predictive validity of teacher licensure test scores in any science classrooms.

We find that basic skills credential test scores are modestly predictive of student achievement in middle school math (with similar relationships as in elementary grades), not predictive of student achievement in high school algebra, and highly predictive of student achievement in high school biology. On the other hand, subject-specific credential tests are a statistically-significant predictor of student achievement only in high school biology, though the magnitudes of the relationships between subject-specific credential tests and student performance in middle school math are comparable to the magnitudes for basic skills credential tests. The relationships that exist are most pronounced when teachers who score in the top quartile of these tests are compared to teachers who scored in the bottom quartile, and there is some evidence that the relationships between a teacher’s subject-specific credential test scores and student performance are more pronounced for students in more advanced courses.

References

Clotfelter, C. T., Ladd, H. F., and Vigdor, J. L. (2007). Teacher credentials and student achievement: Longitudinal analysis with student fixed effects. Economics of Education Review, 26(6): 673-682.

Goldhaber, D. (2007). Everyone’s Doing It, but What Does Teacher Testing Tell Us About Teacher Effectiveness? Journal of Human Resources 42 (4): 765–94. 

Rivkin, S. G., Hanushek, E. A., and Kain, J. F. (2005). Teachers, Schools, and Academic Achievement. Econometrica 73 (2): 417–58.