Mediating effects of trust on the relation between principal leadership and teacher professional learning: A confirmatory investigation of Hong Kong primary schools

This study aimed at identifying the potential mediating effects of trust between principal leadership and teacher professional learning in Hong Kong primary school. Previous studies have addressed how important it was for principals to promote teacher professional learning and consequently student outcomes (e.g., Louis and Marks, 1998; Robinson, LIoyd, & Rowe, 2008). Nevertheless, the factors that possibly functioned in between and the process of their functioning were rarely attempted systematically, esp., in Hong Kong context. To address this research gap, survey data were collected online from a sample of 970 teachers from 32 local primary schools. The two questionnaires, used together, covered a range of principal leadership and school capacity factors. Initial exploration has revealed that, among the school capacity factors those connected to human resources and social capital, i.e., trust, communication, and cooperation in schools, were most likely to be mediators between principal leadership and teacher professional learning (Li, Hallinger, & Ko, in preparation). Following Baron and Kenny’s (1986, 1999) classical causal steps procedure, this study further tested the significance of the indirect effect of principal leadership on teacher professional learning through the mediating effect of trust, using the rigorous bootstrapping approach. Multiple evidence from the chain of mediation analysis and the formal significance tests of the indirect effect showed that, trust was a significant mediator between principal leadership and teacher professional learning in Hong Kong primary schools. When operationalized in seven dimensions, principal leadership related to Strategic Direction and Policy Environment in local education context and Staff Management in schools had significant indirect effects via trust on teacher professional learning, respectively. The mediating effects of trust on principal leadership in terms of Leader and Teacher Growth and Development and Teaching, Learning and Curriculum, independent of other leadership factors, were not significant, which were the case with the other three leadership dimensions. Unlike the other three, these two dimensions, individually and via the nonsignificant effect of trust, had a significant direct effect and total effect on teacher professional learning, respectively. Despite the cross-sectional design, the causal inferences permitted by the mediation analysis and bootstrapping approach made the generalization in local context possible. The implication was that, principals should establish trust in schools, while adjusting their strategic direction and approaches to responding to local educational reform, and emphasizing staff professional development and management. Last but not least, instructional leadership on teaching, learning and curriculum should also be valued.