We develop a theoretical and empirical basis for the design of teacher professional development studies. We build on previous work by (a) developing estimates of intraclass correlation coefficients for teacher outcomes using two- and three-level data structures, (b) developing estimates of the variance explained by covariates, and (c) modifying…

Growing interest in teaching quality and accountability has focused attention on the need for rigorous studies and evaluations of professional development (PD) programs. However, the study of PD has been hampered by a lack of suitable instruments. The authors present data from the Teacher Knowledge Assessment System (TKAS), which was designed to…

Objectives: Group-randomized designs are well suited for studies of professional development because they can accommodate programs that are delivered to intact groups (e.g., schools), the collaborative nature of professional development, and extant teacher/school assignments. Though group designs may be theoretically favorable, prior evidence has…