“…It has been conceptualized and operationalized differently in different research settings without final agreement on which and how many interrelated characteristics are needed to operationalize and measure PLCs (Lomos, 2017). The conceptual challenge with the PLC is on its multidimensional and multilevel nature (De Neve et al, 2015;Sleegers et al 2013): studies emphasize the importance of different dimensions differently: same dimension can be treated as a key dimension (Hord, 2004), it is not mentioned (Hord, 1997(Hord, , 2004 or it is mentioned as supportive condition (Louis & Kruse, 1995). Due to these challenges PLC is still in a developmental stage of theory building Vescio, Ross, & Adams, 2008), and it has proved difficult to measure (Lomos, 2017).…”