“…While these aspects contribute to a more comprehensive definition of TPL, they lack specific mention of how teachers themselves perceive and describe their learning as professionals, instead emphasizing researchers' conceptions. While research exists on teachers' understanding and use of PBL (e.g., Hovey & Ferguson, 2014), these (and related) studies focus on teachers' practices, curricular designs, and perceptions of student learning, viz., post-secondary applications of PBL and student learning (Dahlgren, Castensson, & Dahlgren, 1998;Li & Du, 2015), design principles of PBL (Bo & Li, 2015), and student engagement and teacher perceptions of PBL (MacMath, Britton, & Sivia, 2017;Sivia, Novakowski, Theoretical Framework This study is inspired by Cochran-Smith and Lytle's (2009) seminal research into teacher learning and draws on the principles of their theory of inquiryas-stance 3 , which "is neither a top-down nor a bottom-up theory of action, but an organic and democratic one that positions practitioners' knowledge, practitioners, and their interactions with students and other stakeholders at the center of educational transformation" (pp. 123-124).…”