Research that attempted to investigate the relationship between teacher quality and student achievement began in earnest in the 1960s and 1970s. In a meta-analysis of previous work, Druva and Anderson (1983) uncovered a number of important and statistically significant positive correlations that shed light on the variable of teacher quality in science instruction. Teaching background, teacher behavior in the classroom, and student outcomes were examined. Findings included that teachers with greater content knowledge in a given subject and those with more teaching experience were more likely to ask higher level, cognitively based questions. Teachers with more content knowledge also had a greater orientation toward seeking information from students through questioning and discussion in their teaching compared to teachers with less content knowledge. This was particularly significant in the case of biology teachers. Students’ ability to understand the essentials of the scientific method was positively correlated with the number of science courses (both in biology and in other science disciplines) that their teachers had taken. The degree to which students reported that they “liked science” correlated positively with the number of science courses taken by the teachers.

In 1989, McDiarmid et al. concluded, on the basis of research extant at the time, that teachers’ subject matter understanding and their pedagogical orientations and decisions critically influence the quality of their teaching. “Teachers’ capacity to pose questions, select tasks, evaluate their pupil’s understanding, and to make curricular decisions all depend on how they themselves understand the subject matter.” And in 1995, Chaney demonstrated a relationship between middle-school science and mathematics teachers’ professional preparation and student performance.

These consistently positive correlations appear to support the importance of high levels of preparation for teachers in both content and pedagogy. This preparation and subsequent teaching experience also appear to enhance student achievement.

Hawk et al. (1985) conducted a specific study of the relationship between teachers’ certification in mathematics and their teaching effectiveness. Two groups, each of 18 teachers