O uso de representações em explicações e na argumentação

Abstract

In this study, we assume the importance of science teaching fostering practices in classrooms that are close to those experienced by scientists, and investigate some features related to the epistemic practices inherent to the work of scientists: to argue, to explain, and to represent. Therefore, it is in accordance with the aims of an authentic science teaching. Moreover, the science discourse (in special the chemical one, focus of this study) occurs from the use of multiple representations, thus being characterized as multimodal. From this perspective, we aim at investigating the relationships that can be established between to argue, to explain, and to use representations during such discursive practices. So the research questions addressed in this study are: How do medium level students use representations when explaining and arguing? How does the teacher use representations when explaining and arguing? How Does the teacher contribute to students use of representations when explaining and arguing? The data were collected in a nocturnal second grade medium level class, in a public state school. In the chemistry lessons, students participated in modelling-based activities about interatomic interactions. The lessons were video-recorded, and the parts in which students and the teacher used representations were selected to be analysed. Such parts were transcribed and organized according to their characterization as argumentative or explicative situations. In order to support the analysis, we produced a system of categories identified in both the argumentative and the explicative individuals discourse. The results showed that the main mode of representation used were the concrete one, which is in accordance with the main aims of the activities performed by the students: to produce and test concrete models. Additionally, we identified several aims for using representations in the individuals discourse: to reinforce the speech; to help when individuals have difficulties in expressing their ideas verbally; to substitute specific scientific vocabulary; to check the understanding of conceptual issues, etc. We conclude that the (gestual, visual, concrete, etc.) representations were an important part of argumentation and explanations performed by both students and the teacher, and that the teacher performed particular actions that favour students use of representations. Moreover, we confirmed the contributions of modelling-based activities to students learning, since they foster them to express their ideas in mode distinct from the verbal one (frequently used in chemistry lessons). From the reflections motivated by this study, new research questions that may contribute to the production of other relevant knowledge in the area emerged.