Interações sociais e o discurso sobre o visível e o invisível em aulas de química

Abstract

Our study, starting from interaction and dialogue, aims to understand the elaboration of explanations in chemistry classes, from the point of view of the theoretical and empirical aspects of this knowledge. A teacher and her 26-student-class of a high school first year of a government public school of Belém-Pa participated of the research. A class involving the realization of an experiment about the formation of dust was planned. Four groups of students were formed to carry out the experiment. After observing the experiment, the four groups of students discussed with each other, with the teacher, after that, they discussed with the whole class and the teacher. The dialogues among the groups and with the class were recorded and integrally transcripted. We used microgenetic analysis to study the dialogue of one of the groups without the presence of the teacher, and later with the teacher and the whole class. We identified in the dialogue the sequences from which arose the explanations. In these sequences we used the categories proposed by Mortimer & Scott (2002) to analyze the intentions, the contents, the communicative approach, the interaction patterns and the teacher’s interventions. These analyses made it possible for us to understand and discuss how students elaborate explanations in classes and, in each of them the participation of theoretical and empirical aspects of the chemistry knowledge. Thus, we observed that the explanations which were elaborated by the students took in account knowledge from different origins: empirical observation of the experiment, previous school learning, everyday concepts and the theoretical knowledge shared by the teacher. A dialogical communicative approach was predominant, but, whenever necessary for the elaboration of the explanation to relate the empirical with the theoretical, the communicative approach was predominantly one of authority.