“…schools have traditionally been characterized by teacher privacy and independence (Hargreaves & Fullan, 2012; Kardos & Johnson, 2007; Lortie, 1975; Organisation for Economic Co-operation and Development, 2013), yet higher levels of teacher peer support and collaboration have been linked to greater student achievement, innovative climate, and improved reform implementation and sustainability (Coburn, Mata, & Choi, 2013; Frank, Zhao, & Borman, 2004; Leana & Pil, 2006; Pil & Leana, 2009). Reformers have therefore argued for the “de-privatization of instruction,” or for increasing teachers’ engagement with peer observation, feedback, and support (Hargreaves & Fullan, 2012; Quinn & Kim, 2017; Supovitz, 2002; Vanblaere & Devos, 2016; Wahlstrom & Louis, 2008). However, school systems have struggled to achieve that goal.…”