Instructional leadership and teacher professional learning: The mediating role of teacher leadership and the moderating role of distributed leadership

This study examines the relationship between instructional leadership (IL) and teacher professional learning (TPL) through the mediating role of teacher leadership (TL) and the moderating role of distributed leadership (DL) within Türkiye's centralized education system. Grounded in a social-constructivist approach, the study posits that TPL is linked to interactive and shared processes. Data from 765 public school teachers in Ankara were analyzed using structural equation modeling, bootstrapping, and moderated mediation analysis. Results from the unconditional model demonstrated a low-level yet significant association between IL and TPL, with TL serving as a partial mediator in this linkage. Findings from the conditional model, based on moderated mediation analysis, revealed that the associations within the IL-TPL, IL-TL, and IL-TL-TPL pathways vary significantly depending on the level of DL. While high DL levels strengthened these positive interactions, low DL conditions were associated with weakened or reversed linkages, suggesting bureaucratic resistance. Among control variables, gender and experience significantly predicted TPL, favoring female and relatively less-experienced teachers. Theoretically, this study conceptualizes TPL through the interplay between vertical and horizontal leadership processes within an integrated framework. Practically, the findings suggest that strengthening collaborative leadership structures is essential for the sustainability of reform-oriented professional learning.