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…

This study examines the impact of 2 professional learning community (PLC) classroom practices on the English Language Arts achievement of California's most at-risk subgroups between selected higher- and lower-performing elementary schools in a southern California school district. The conclusions from this study agree with the body of research,…