Professional development has been too often divorced from practice, taking place outside the school or the classroom. Developmental Education works from another point of view by innovating classroom practices through theory-driven, systematic, purposeful and reflective collaboration between teacher trainer and teachers inside the classroom. From our Vygotskian perspective we guide the teachers in such a way that they feel confident enough to innovate their personal beliefs and conceptions for working in a developmental way. This chapter addresses the main characteristics of such an implementation process and focuses on the creative induction process that teachers need to go through with the help of a teacher trainer. Collaboratively, the teachers significantly transform some of their basic educational concepts, and thus create valuable and flexible knowledge for promoting meaningful learning in young children in the context of a play-based curriculum.