The purpose of the study is to reveal the effects of School-based Professional Learning Communities(PLCs) on teachers and students including the path analysis. In particular, this study tried to find the possibility of PLCs as a factor in determining effective schools by revealing the paths of effectiveness in the processes of schooling. Also, it was attempted to overcome the ‘input-output’ studies of school effectiveness, which is perceived as a limitation of the existing school effect research. To this end, t/F verification and statistical analysis of multi-layer structural equations (MSEM) were performed using data from the 4th and 6th years of the Gyeonggi Education Panel Study(GEPS). Section 1 of Chapter 4 verified the differences in ...