Researchers often presume that it is better to use administrative data from grades 4 and 5 than data from grades 6 through 8 for conducting research on teacher effectiveness that uses value-added models because (1) elementary school teachers teach all subjects to their students in self-contained classrooms and (2) classrooms are more homogenous at…

Progress in International Reading Literacy Study (PIRLS) provides international comparative data about students' reading achievement after four years of primary schooling, while also measuring trends over time, monitoring curricular implementation, and identifying promising instructional practices. Conducted on a regular 5-year cycle, PIRLS has…