Multivoicedness and univocality in classroom discourse: an example from theory of matter

The analyses of talk amongst students in three episodes, video recorded from a teaching sequence on the particle model for Brazilian students (age 14‐15) is presented. The analysis has two dimensions: the discoursive dimension is an attempt to understand how meanings are constructed in the classroom as a result of discoursive interactions; the conceptual dimension comprises the description of the patterns of evolution of ideas of matter based on the notion of a conceptual profile of matter, in which conceptual and historical features of the atom concept are profiled with pupils’ and adolescents’ ideas on atomism. From the students talk we can hear the interaction among different ‘voices’, representing different zones of a conceptual profile of matter. In this interaction, the students resort to both ‘authoritative’ and ‘internally persuasive’ discourses. The analysis emphasizes the role of these two types of discourse and of epistemological and ontological obstacles in the construction of scientific meanings in the classroom.