Journal Issue: Excellence in the Classroom Volume 17 Number 1 Spring 2007
The Benefits-and Costs-of Certification
Every state has its own procedures for certifying teachers, and every public school is expected to hire teachers certified by the state. All states require a bachelor’s degree, and all but two require applicants to pass at least one certification exam that covers general knowledge and subject-area knowledge, as well as pedagogy. Some states require high school teachers to have a major in the subject area that they teach, and most require teachers to complete coursework in education. Further, most teacher candidates must spend time as a student teacher before becoming fully eligible to teach in a public school system.7
Donald Boyd, Daniel Goldhaber, Hamilton Lankford, and James Wyckoff raise a salient policy issue regarding these certification processes. In theory, certification can improve the quality of teachers in the classroom by establishing a floor on quality. To the extent that certification can distinguish bad teachers from better teachers, it can keep the worst teachers from entering the classroom. However, certification can fail to meet its goal in two ways. First, it can fail to distinguish good teachers from bad. Second, it may drive away potentially good teachers. If the certification process itself is so onerous that it keeps good teachers from pursuing a teaching career, then it may in fact lower the overall quality of teachers, even if it does screen out the worst teachers. Assessing the value of certification systems therefore requires evaluating both their ability to screen out the worst candidates and the extent to which they discourage potentially good candidates.
There is surprisingly little research that sheds light on how any element of certification affects classroom teaching. This does not mean that certification has no effect, just that there is no convincing evidence one way or the other. What little research there is suggests that teachers who score higher on exams tend to add more to the achievement gains of their students than do their lower-scoring peers, though these effects are not large. The authors were not able to identify any high-quality studies of how coursework or field experiences influence teacher effectiveness. The best evidence for the effect of field experience, and particularly student teaching, comes from the tendency of teachers to improve over their first few years. Students of first-year teachers, on average, learn less than students of more experienced teachers—a finding that suggests that classroom experience helps make teachers more effective.
Many states have introduced new routes to teaching that lessen coursework requirements. These new routes vary in their characteristics and content. Several studies of the most highly selective of these alternative routes, Teach for America, find that TFA teachers appear to perform at least as well in math as do the other teachers in their school, though (depending on the analysis) not quite as well in reading. But TFA is not representative of all alternative routes because it is highly selective, national, and aimed only toward recent college graduates. Given the enormous investment in teacher preparation and certification and the potentially negative consequences of certification for teacher supply, the lack of evidence is disturbing.