“…Although RETs have become a common approach to science teacher PD, and one that has received a great deal of support in the United States from organizations such as the National Science Foundation (NSF), research into the effectiveness of these programs as catalysts for modifying teacher practice is limited (Blanchard et al, 2008;Capps et al, 2012;Dixon & Wilke, 2007;Hughes, Molyneaux, & Dixon, 2012;Pop, Dixon, & Grove, 2010). Much of the earlier work following teacher PD programs has been based on teacher self-report, although more recent work into RETs has begun to systematically focus on changes in teacher thinking (Dixon & Wilke, 2007;Schwartz, Weserlund, Garcia, & Taylor, 2010), teacher practice (Blanchard et al, 2008;Hughes et al, 2012;Pop et al, 2010), and subsequent student achievement (Silverstein, Dubner, Miller, Glied, & Loike, 2009). The research presented here follows this more recent tradition as it examines the effectiveness of two different forms of the RET programs in shaping teacher beliefs, affect, and practice to identify the most essential aspects of such programs to support teacher learning.…”