Samenvatting

Educational practices are complex and value-laden, shaped through the interplay of societal expectations, pedagogical commitments, organisational arrangements, and everyday interactions between teachers, pupils, and colleagues. Teachers do not act as neutral implementers of external prescriptions; rather, they interpret situations, exercise judgement, and contribute to shaping and renewing practice. This dissertation therefore conceptualises teachers as critically reflective professionals who co-construct educational practices with others. The study examines teacher agency as a socioculturally situated and relational phenomenon. Agency is understood as teachers’ capacity to purposefully shape professional action and contribute to the development of practice, while professional identity is simultaneously formed and renegotiated. From a subject-centred sociocultural perspective, agency is not treated as an individual trait but as an emergent, normatively charged process visible in teachers’ meaning-making, positioning, and action within and across practices. The empirical setting consists of dual learning contexts in which a professional master’s programme is intertwined with teachers’ workplace practices. These contexts connect off-the-job and on-the-job learning within a dynamic constellation of practices. Their potential can be described in terms of affordances: action possibilities arising in the interaction between teachers and their environments. Affordances become meaningful when teachers recognise, interpret, and mobilise them in relation to their aspirations and workplace conditions. The dissertation addresses two main questions: (1) Which processes underpin the development of teacher agency across domains of professional practice? and (2) How does teacher agency develop over time, and how do teachers interpret the contribution of participation in a dual learning context? The dissertation comprises a theoretical synthesis and three empirical studies. The synthesis integrates research on workplace learning, professional identity, relational agency, and normative perspectives on education, resulting in an analytical framework specifying agency across four interconnected domains: meaning-making, professional identity, collaboration, and organisational processes. Within these domains, twelve agentic qualities are identified as sensitising concepts for tracing agency as a dynamic, context-dependent phenomenon. Empirically, the study adopts a longitudinal multi-case design in which six teachers from primary, secondary, and special education were followed over two years through repeated interviews, supplemented by interviews with colleagues, school leaders, teacher educators, and document analysis. Across cases, agency development appeared non-linear and uneven, closely connected to teachers’ engagement with systemic tensions, such as tensions between pedagogical ideals and established routines or between taking initiative and fostering shared ownership. Under supportive conditions, such tensions functioned as catalysts for reflection, repositioning, and new forms of practice. Agency was strengthened when programme-related resources (assignments, concepts, feedback, coaching) were meaningfully connected to teachers’ practice-based questions, and when relational and organisational conditions enabled dialogue, experimentation, and shared responsibility. Dual learning contexts do not automatically foster agency; their value depends on how teachers and others co-construct affordances across settings. The dissertation contributes a socioculturally grounded framework for analysing teacher agency development as situated, relational, and normatively oriented, and offers implications for designing professional learning that supports meaning-making, identity work, collaboration, and organisational conditions for sustainable educational development.