This paper examines the quality and benefits of a support program for schools offering various interventions and their impact on school leadership, school development and school quality in schools in challenging circumstances. This five-year longitudinal mixed methods study is based on a sample of around 150 schools in North Rhine-Westphalia, Germany. Over a period of three years, half of the schools experienced further measures to professionalize school leadership (e.g., coaching of school leaders, continuous professional development program) and support school development (additional financial resources, school development consultancy). The analyses are built on two different surveys of staff and school leaders on the work situation and on the interventions assessed each program year. In addition to a descriptive evaluation of the quality assessments of staff and school leaders, regression analyses are conducted to examine the impact of specific program components on selected school quality characteristics during the program period. Since the program was implemented at the school level, the analyses were conducted accordingly. Using a comparison group design, it is possible to compare the changes in project schools and comparison schools and relate them to the program components. To capture changes in schools based on questionnaire data, the effect size Cohen's d (Cohen, 1988) was calculated, which relates to the practical relevance of the results. The results of the study show the very positive assessment of the program’s quality and benefits and its positive consequences on the organization’s quality. The regression analyses demonstrate that positively perceived outcome qualities of the interventions are associated with improvements in numerous dimensions of school quality, such as cooperative leadership. For example: The school members’ positive perception of the benefits (β = .26**) and achieved goals (β = .28**) as well as their perception of an increase in competence development (β = .25**), behavioral (β = .27**) and organizational (β = .15*) change through the school’s work with a process consultancy for school development is associated with an improved coordination of action of the steering group as perceived by the employees. Furthermore, the effect sizes indicate that most schools involved in the program showed better development over time than the comparison schools. Overall, the findings provide evidence for the effectiveness of school development programs on school leadership and school improvement. Based on these results, the interventions will be discussed in terms of their effects and the necessary conditions for successful implementation, along with their practical implications.

Cohen, J. (1988). Statistical Power Analysis for the Behavioral Sciences (2nd ed.). Routledge. https://doi.org/10.4324/9780203771587