<p style="text-align: justify;">The paper presents a conception of action research-based pedagogy in primary education, which is carried out by prospective primary school teachers, i.e. student teachers of a Lithuanian university. Action research is an appropriate way to implement educational practices that take into account the needs of each pupil, by solving problems and creating authentic educational content in each classroom. Since pupils&#39; critical thinking skills in argumentation are a weak area in primary school in Lithuania, the article describes the methods and solutions to the problems applied in the practical activities. It should be noted that the choice of active learning methods, such as debates and group work, not only helped to improve the achievement of primary school pupils, but also increased their motivation to learn.</p>