Teachers' conceptions about three teaching strategies - lectures, experimental classes and demonstrations - are investigated, as well as their process of re-meaning, heading coherence with constructivist principles of teaching and learning, that teachers accomplish in a professional development program. For the re-meaning to occur, teachers experienced phases of awkwardness, operationalization and consciousness and had the opportunity, on the way, to deepen knowledge on constructivism with respect to its translation to classroom instances. Departing from naïve conceptions, they realized it is not the type of activity what determines a constructivist teaching, but the way it is approached and considered in the classroom and in the didactic sequence.
Re-Meaning of Didactic Activities; Constructivism in the Classroom; Teachers' Formation