Structured Counselor–Teacher Collaboration as an Interdisciplinary Model for Enhancing Inclusive School Climate: A Quasi-Experimental Study

Inclusive education requires not only classroom-level adaptations but also coordinated interdisciplinary practices that strengthen the institutional conditions supporting diverse learners. However, counselor–teacher collaboration in many schools remains informal and episodic, limiting its potential contribution to an inclusive school climate. This study evaluated the effectiveness of a 12-week Structured Counselor–Teacher Collaboration (SCTC) program designed as a cyclical and replicable interdisciplinary model. A multi-site cluster quasi-experimental design with matched non-equivalent control groups was implemented in 12 public inclusive junior secondary schools in Yogyakarta, Indonesia (6 intervention; 6 control), involving 360 teachers (n = 180 per condition) and 24 school counselors as facilitators. Teachers completed the 35-item Inclusive School Climate Scale (ISCS) at pre-test and post-test. Data were analyzed using two-level linear mixed-effects modeling (teachers nested within schools) with pre-test scores as covariates. Results showed that the intervention significantly improved inclusive school climate compared with routine practice (B = 0.41, p < 0.001), yielding a moderate-to-large adjusted effect (Hedges’ g = 0.76). Dimension-level models indicated the largest gains in collaborative professional culture and perceived belonging. Implementation fidelity was high (82–91%). These findings suggest that institutionalizing structured counselor–teacher collaboration can serve as a promising approach for enhancing inclusive school climate in secondary school contexts.