Online discussions are commonly used as learning activities in higher education. One of the rationales behind their use is to enhance students' competence in critical thinking and rational argumentation. In the research field, several approaches to critical thinking and rational argumentation are suggested, and several frameworks for analyzing online educational discussions are employed. In this article, online discussions from an introductory philosophy course are analyzed. The microstructure of arguments (how arguments are backed) and the macrostructure of argumentation (how arguments are linked together in chains of arguments and counterarguments) are used as analytic tools. The categories for analysis are based on Toulmin's argument model. The aim here is twofold. First, the article explores what occurs in online discussions in an introductory philosophy course where competence in argumentation is a specific learning objective, analyzed using the categories of the microstructure of arguments and the macrostructure of argumentation. Second, the article discusses how suitable the categories from Toulmin's model are for such analysis. The analysis reveals that the students eagerly discussed the topic, showed an understanding of the topic, and employed subject knowledge. Yet, their discussion posts tended to be associative and unaddressed. The categories of the microstructure of arguments and the macrostructure of argumentation proved powerful tools for analysis. The analysis coincides with the students' and teachers' own evaluation of argumentation in the discussions, yet it provides a more justified, detailed picture of the strengths and weaknesses in the students' argumentation. Nevertheless, important qualities of the discussion are not revealed by these categories. One recommendation for teaching and facilitation is to provide students with an elaborated conception of rational argumentation.

His main research interests are formative assessment, digital learning and doctoral education. Jens Breivik is associate professor in education. His area of research is teaching and learning in higher education. His background is in scholarship of teaching and learning in HE and philosophy of education. He has a particular interest in analysis of students' critical thinking and argumentation skills. He is a member of the research group