Abstract This study used a mixed-method design to examine the relationship between open classrooms as a form of professional development and teacher efficacy in the arenas of instructional strategy, classroom management, and student engagement. This study was conducted with sixth to eighth grade teachers in a middle school, located in central New Jersey. Teachers were surveyed using the Tschannen-Moran and Woolfolk Hoy's (2001) Teachers' Self-Efficacy Scale (TSES) 24 question Likert scale. They...