classroom instruction in science include powerful influences outside school (e.g., Lareau, 2000), within school systems at the state or district level (Spillane, 1996, 2000), and at the school and classroom level (Cohen, Raudenbush, and Ball, 2001). We acknowledge this broad range of factors and choose to focus here primarily on the conditions that support student learning at, and immediately surrounding, the classroom level.

In this chapter we review what researchers have found about the influence of three critical components—teacher knowledge, teachers’ opportunities to learn, and instructional systems—on students’ science learning. Two questions guide our discussion of the literature in this chapter. First, what are the implications of research on student learning for school and classroom-level supports for instruction? Second, where do empirical links between classroom and school-level supports for instruction and student learning exist?

It is a truism that teachers must know the content that they are to teach. While no teacher could adequately support student learning without first mastering the content of the curriculum herself, effective teaching requires more than simple mastery. Quality instruction entails strategically designing student encounters with science that take place in real time and over a period of months and years (e.g., learning progressions). Teachers draw on their knowledge of science, of their students, and of pedagogy to plan and enact instruction. Thus, in addition to understanding the science content itself, effective teachers need to understand learners and pedagogy design and need to monitor students’ science learning experiences.

Research findings generally support the notion that higher levels of teacher subject matter knowledge contribute to higher student achievement (Chaney, 1995; Goldhaber and Brewer, 1997, 2000). This finding holds across a range of measures of teacher knowledge. Having a major or a graduate degree in a subject contributes to a teacher’s effectiveness and higher student achievement (Goldhaber and Brewer, 1997, 2000; Chaney, 1995). Monk (1994) found that the number of postsecondary courses that mathematics and science teachers have taken is associated with incremental gains in student scores. Although there has been less research on the knowledge of science teachers (and of elementary science teachers in particular), the existing evidence supports this pattern. In a meta-analysis of 65 studies, Druva and Anderson (1983) found that student science achievement was positively related to both the number of biology courses and the overall number of science courses