Conceptual Replications of the Teacher Study Group Approach to Professional Development in Vocabulary.

We discuss an original study and two replications conducted over 18 years examining the impact of Teacher Study Group (TSG) in Vocabulary, a professional development (PD) approach for improving pedagogy and student learning. Study 1 focused on the design and development of the PD and included a small-scale randomized controlled trial to assess the efficacy of the TSG model with grade 1 teachers. Study 2 was a scale-up study conducted in grade 1. Study 3 examined the efficacy of the TSG when implemented with grade 8 teachers of American history. We highlight similarities and differences in methodology and results among the studies and conclude with a discussion of the pattern of findings followed by a reflection on issues emanating from this line of research. [ABSTRACT FROM AUTHOR]