Enhancing Teachers' Interdisciplinary Professional Development through Teacher Design Teams: Exploring Facilitating Conditions and Sustainability

Teachers in secondary vocational education face challenges in interdisciplinary teaching due to their traditional teacher education within specific subject domains. Collaborative efforts-like those implemented in Teacher Design Teams (TDTs)-can prepare and support teachers for interdisciplinary teaching. Research has demonstrated the factors determining the effectiveness of TDTs. However, it is noted that the sustainable continuation of TDTs remains uncertain over the years. This research investigates the conditions that facilitate the sustainability of TDTs within the context of interdisciplinary teaching. Over the course of three school years, this qualitative study monitored 14 teachers participating in four TDTs within the context of an interdisciplinary vocational education course. During the initial two school years, the TDTs received external support from the main researcher, transitioning to an autonomous operation in the third school year. A yearly interview with each participating teacher and meeting reports were collected and analysed with thematic analysis. One of the main findings reveals that while the internal coach contributes to supporting TDTs' progress, the support of the school leader is particularly crucial for sustainability. Although this study focused on school-based TDTs, it underscores the importance of support from outside the school for TDTs' sustainability.