Abstract
The first part of the paper presents and analyzes the term horizontal competences, as it is defined in the institutional texts of the European Union, as well as the possibility of their development within the framework of the educational group of “Argumentation and Disputation”. The second part of the paper describes the context of the educational groups as well as the learning outcomes of the students’ participation in them. The third part of the paper presents the views of the students of the Experimental Lyceum of the University of Patras in relation to the development of horizontalcompetences within the framework of the educational group of “Argumentation and Disputation”. The paper concludes with conclusions on the contribution of educational groups to the development of students’ horizontal competences