The ratification of the UN CRPD by Switzerland in 2014 committed the country to establishing an integrative education system at all levels.  The text of the agreement ratified by Switzerland differs from the original: according to Article 24, Switzerland does not guarantee an inclusive education system, but an "integrative education system at all levels". A decade later, the topic of integrative schooling is widely discussed in Swiss educational practice and public discourse. Political initiatives in various Swiss cantons are increasingly advocating for separative measures, such as reintroducing small special classes or remedial groups. These discussions stem from criticism of the implementation of integrative schools, with evaluations indicating that special education teachers, therapists, and school administrators and general teachers alike generally view integration positively and feel capable of managing it. However, general teachers often report feeling overwhelmed and less persuaded about the demands of integrative education (Graubünden Department of Education, Culture, and Environmental Protection, 2021).

Research emphasizes the crucial role of school leadership, with leaders acting as "change agents" who bridge government reforms and school-specific initiatives (Huber & Muijs, 2010; Hallinger & Huber, 2012). However, the role of school leadership in the implementation process  of integrative respectively inclusive schools still remains underexplored (Van Mieghem et al., 2020). Existing studies suggest that school leaders influence inclusive education primarily through fostering positive attitudes and promoting teachers’ self-efficacy in implementing inclusion (Ainscow et al., 2013). Empirical evidence consistently underscores the importance of teacher attitudes and self-efficacy as critical factors for successful inclusive practices (Mudhar et al., 2024).

Multiprofessional collaboration among teachers, special educators, therapists, and other staff is another essential factor for successful inclusive education (Frohn et al., 2023). However, such collaboration is often challenging to achieve and remains aspirational in many schools. The success of multiprofessional collaboration depends significantly on school leadership, which must coordinate actions and foster cooperation.

The present study highlights that school leaders play a critical role in shaping inclusive schools by fostering teacher self-efficacy and multiprofessional collaboration. Cooperative leadership models and coordinated actions in school development processes are particularly significant. Effective school leaders involve teachers in decisions and development steps and facilitate networking among stakeholders within and beyond the school.

Sample This study is based on data from a cross-sectional online survey conducted as part of a Swiss National Science Foundation-funded project. Data were collected between September 2022 and December 2023 across 12 German-speaking Swiss cantons. The analyzed sample includes 938 teachers, 84.7% female, aged 22 to 65 years (mean: 43.0, SD: 11.8). Among them, 43.2% teach kindergarten or lower primary, 75.4% primary school, and 15.6% secondary school, with some teaching at multiple levels. Instruments Teachers were surveyed on different aspects of inclusive schools and leadership characteristics: Inclusive practice was assessed using a tool based on Booth & Ainscow’s Index for Inclusion (2011) and the Institute for Educational Monitoring’s questionnaire (2008). The instrument focuses on Inclusive Policies, Practices, and Culture. Two indices were constructed: “My Teaching” evaluates inclusive practices in classrooms, including collaboration with students and addressing diversity. “Our School” examines inclusive learning at the school level, group organization, individualized plans, and diversity promotion. Cooperative leadership characteristics were measured using Hulpia et al.’s Distributed Leadership Inventory (2009). In addition, a custom scale was used to evaluate principals' ability to coordinate actions related to inclusive school development processes. Multiprofessional collaboration was assessed with Dizinger et al.’s (2011) framework, focusing on lesson preparation and student-specific issues. Three subscales covered collaboration dimensions and their relieving effects, supported by confirmatory factor analysis. Amrhein et al.’s (2018) scale added cross-functional aspects like shared goals and responsibilities. Cooperation with external partners was measured using a SEIS (2008) scale. Self-efficacy beliefs with regard to implementing inclusive learning was measured using the KIESEL scale (Bosse et al., 2014). Covariates included roles, school levels, gender, and age. Empirical Model and Hypotheses Mediation analyses tested leadership effects such as cooperative leadership and ability to coordinate on inclusive practices. The first model assessed total effects of leadership variables. A second model included two potential mediators: self-efficacy beliefs and multiprofessional collaboration. Regression models analyzed direct and indirect leadership effects on classroom and school-level practices. Covariates controlled for confounders, and missing data were addressed using Full Information Maximum Likelihood (FIML) estimation in R’s lavaan package (Rosseel, 2012).

Results Teachers rated their practices and schools as inclusive overall. Inclusive teaching and inclusive school correlated with each other at r=.379 (p < 0.001). Collaboration ratings varied, with common lesson preparation rated lowest. In addition, it becomes clear that teachers on average have neutral to rather positive self-efficacy expectations regarding inclusion. Both leadership characteristics are positively associated with inclusive practices: The extent of cooperative leadership is significantly positively associated with a stronger inclusive practice at both levels, classroom and school level. The ability of principals to coordinate actions is particularly important for inclusive practice at school level. Both effects are mediated by teachers self-efficacy beliefs and their level of collaboration. Conclusion In addition to previous studies, the present study emphasizes that school leadership characteristics play a role in shaping inclusive schools by fostering teachers’ self-efficacy beliefs related to inclusion and promoting multiprofessional collaboration within schools. The findings highlight the importance of cooperative leadership models and the role school leaders have in coordinating actions to develop inclusive schools. School leadership is thus tasked with involving teachers in decision-making and developmental steps, as well as coordinating exchange and networking among various actors inside and outside the school. When school leaders succeed in this task, teachers are more likely to collaborate with different stakeholders and feel more self-efficacious in implementing inclusive teaching. Both aspects are essential prerequisites for inclusive practices at both the classroom and school levels.

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