CHARACTERISATION OF STUDENTS’ ARGUMENTATIVE REASONING Rosária Justi, Marina Martins and Stefannie Ibraim Universidade Federal de Minas Gerais, Brazil Abstract: Based on Douglas Walton and colleagues’ ideas, we propose a way to analyse students’ argumentative reasoning, and show how a debate among them can be analysed. students participated in a debate about the question: Should fast-food restaurants be responsible for their costumers’ obesity and health problems? Our analytical proposal showed to be less complex and subjective than other proposals found in the literature, since it is based on clear principles from Walton’s ideas, and allows the understanding of students’ way of reasoning when participating in argumentative situations. Keywords: Argumentative reasoning, students’ ideas INTRODUCTION: RATIONALE AND AIMS Students’ argumentation has been analysed from different perspectives. Most of them involve the identification of basic elements of arguments (like claim, evidence, and justification), and associate the quality of argumentation to their presence. Although such analyses could be helpful for some purposes, they provide a limited view on how students organise their ideas to defend them. One distinct way to analyse students’ arguments was proposed by Kelly and Takao (2002). They focused on the relative epistemic status of students’ written propositions, and on the links within and across levels to analyse students’ longer chains of reasoning. In order to do so, they defined the epistemic level based on the content area of the arguments, and designed representations of the hierarchical structure of students’ statements from specific to theoretical ones, that shows links across epistemic levels. The main limitations of this model concern it being specific for a given content area; the disagreement between distinct experts when classifying the epistemic levels of students’ arguments; and the vagueness associated with the assessment of inferential connections. The purpose of this paper is twofold. Based on Douglas Walton and colleagues’ ideas, we propose a way to analyse students’ argumentative reasoning, and show how a debate among them can be analysed. So, the paper is guided by the question: How students’ argumentative reasoning expressed in an oral debate can be characterised? THEORETICAL BACKGROUND Walton is mainly known from his several argumentation schemes, inferences that represent common types of argumentation (Walton, 2006). However, they are useful to categorise arguments rather than to characterise argumentative reasoning that support a debate. In order to do so, we took into account some of the basic ideas used by Walton and his collaborators, briefly summarised from Walton (2006) and Walton, Reed, and Macagno (2008) as: (1) An argument is a social and verbal means of trying to resolve, or at least contend with, a conflict of ideas that has arisen between two parties engaged in a dialog about a questionable point, by eliciting premises (reasons) and conclusions on both sides. (2) As dialogues are dynamic,