School leadership development and academic achievement Effectiveness of the High Performing Schools programme

Many education systems face declining levels of academic achievement. Consequently, educational policymakers and practitioners alike are seeking ways to improve academic performance. This study examines the effectiveness of a specific school leadership development programme in the Netherlands called the High Performing Schools (HPS) programme. The HPS programme is a continuing professional development (CPD) initiative focused on evidence-informed school and leadership improvement, targeting school personnel in two different versions: HPS for leadership teams (principals and middle-level leaders) and HPS for whole-school teams as professional learning communities (PLCs). Forty-seven primary schools participated in the HPS programmes between 2018 and 2021. A quasi-experimental design was implemented, and public academic attainment data were used to assess the effectiveness of the programme. The academic achievement at the school level in the academic year 2021 and 2022 was compared between the 47 participating schools and a comparison group of 6110 schools using ANCOVA with post-hoc tests. The analyses indicate that schools that participated in the HPS programme outperformed comparison schools. Moderate to large gains in achievement were found, equivalent to six to eight months of additional learning progress. Schools that participated in the PLC version of the programme performed best. The effects were statistically significant for math and writing, while no significant effects were found for reading. We conclude that the HPS programme shows promising results.