Semantic waves and the epistemic dimension in the classroom discourse of chemistry

Abstract

This article presents an analytical tool for studying the epistemic dimension of the classroom discourse of Chemistry. Based on the concept of semantic waves derived from the Theory of Legitimation of Codes and the notion of pedagogic link-making, the analytical tool seeks to explore the forms and the organization of chemical knowledge in the instructional discourse. In the analysis´ model used in the construction of semantic profiles we included the different levels of chemical knowledge and notions of systemic linguistics in relation to contextualization / decontextualization in academic discourse. The developed tool was applied in the illustrative analysis of two classroom episodes of two chemistry teachers in high school. The analysis revealed different variations in the semantic profiles among teachers, whose movements were associated to the presence of pedagogic link-making. The tool has demonstrated the potential to differentiate the forms of chemical knowledge present in teachers' classroom discourse and the discussion of the results relates the variation and distribution of these forms with the segmentation and construction of scientific knowledge.