“…Most research has yielded disappointing results with regards to the effectiveness of PD in helping teachers improve their knowledge and instructional practices (e.g., Garet et al, 2008;Garet et al, 2011;O'Dwyer et al, 2010;Powell, Diamond, Burchinal, & Koehler, 2010). Results are even more disappointing regarding impact on student learning and achievement (e.g., Garet et al, 2008Garet et al, , 2011O'Dwyer et al, 2010;Powell et al, 2010). Every year, governments around the world invest astronomical amounts of money on traditional PD activities such as seminars, talks, workshops, and conferences (Gersten, Dimino, Jayanthi, Kim, & Santoro, 2010;Yoon, Duncan, Lee, Scarloss, & Shapley, 2007), brief and sporadic events in which teachers tend to be passive recipients of information, having no opportunities to collaborate with others.…”