School leadership effects revisited: a review of empirical studies guided by indirect-effect models

Fourteen leadership effect studies that used indirect-effect models were quantitatively analysed to explore the most promising mediating variables. The results indicate that total effect sizes based on indirect-effect studies appear to be low, quite comparable to the results of some meta-analyses of direct-effect studies. As the earlier indirect-effect studies tended to include a broad range of mainly school organisational conditions as intermediary variables, more recent studies focus more sharply on instructional conditions. The results of the conceptual analysis and the quantitative research synthesis would seem to support conceptualising educational leadership as a detached and ‘lean’ kind of meta-control, which would make maximum use of the available substitutes and self-organisation offered by the school staff and school organisational structural provisions. The coupling of conceptual analysis and systematic review of studies driven by indirect-effect models provides a new perspective on leadership effectiveness