Making a difference: insights from in-service teachers’ professional development for implementing differentiated instruction in the secondary school classroom

Abstract

This longitudinal mixed-methods study explored how in-service professional development in a Dutch comprehensive secondary school corresponded with teachers’ self-reported differentiated instruction (DI) practices across five domains. Quantitative data were collected using a one-group repeated measures design, followed by nominal group interviews for qualitative insights. Multilevel growth modeling (teacher n = 124, repeated measure n = 271) indicated significant increases in self-reported DI practices within the activities and materials domain. No significant effects were found in the other domains. Teachers attributed the increases to peer workshops, structured lesson design with implementation support, and peer consultations. Structural constraints, such as time limitations and departmental compartmentalization, were identified as barriers. Conversely, strong school leadership, a collaborative school culture, and a shared belief in the value of DI were seen as essential enablers. These findings underscore the importance of aligning professional development with supportive school conditions to foster sustainable instructional change in DI.