In this work, we show the results from a research made in a curricular innovation situation, whose main focus was to assess the performance of a teacher which implemented a teaching sequence on the concept of mass. This process began by a revision of the concept of mass in three different frameworks, namely classical mechanics, electromagnetism and relativity, with the purpose of addressing the epistemological changes of the subject from Newtonian mechanics to relativity. This revision yielded a written material about the theme and was employed in the development of the teaching sequence, which had as main methodology the Design Based Research. Our main research focus concerns the performance of the implementer teacher and his appropriation of the underlying didactic intention. In order to assess how effectively this teacher did absorb the intentions of the course he delivered, we relied on Chevallard’s Didactic Transposition Theory. Data were extracted from recordings of the teacher’s classes and the subsequent analysis has shown that there may be a relation between the difficulties he had in conveying the didactic intention and the innovative character of the contents involved. Our results indicate that these difficulties are directly related with the very nature of scientific knowledge and, in fact, belong to the realm of epistemology.
didactic transposition; teaching-learning sequence; teaching relativity; mass-energy equivalence; epistemology