Didactic suitability criteria in the practical argumentation of mathematics teachers’ educators

Abstract

[Objective] The objective was to analyse the practical arguments of a group of mathematics teachers’ educators during the assessment of the design of a didactic unit on functions for secondary education students (aged 15–16). [Methodology] A qualitative methodology was followed, which consisted of an intrinsic case study, where eight mathematics teachers’ educators, who knew the Didactic Suitability Criteria construct, were involved in a Lesson Study cycle. In the reflection stage of this cycle, the participants used this construct to assess the design of the didactic unit (teacher’s plan and students’ dossier). The emerging practical arguments were structured using Toulmin’s model. [Results] Three results are highlighted: first, the assessment of the didactic unit with the components of Didactic Suitability Criteria allowed it to identify the aspects that favoured and that required improvement in the teaching and learning process of functions; second, these components were used as data, backings, and warrants in the practical arguments elaborated by the participants, due to their knowledge of this construct; and third, the participants used all these components to assess the didactic unit and argued their proposals of change based on such components. [Conclusion] The role played by Didactic Suitability Criteria in the participants’ practical argumentation was as a generator of practical arguments and as a central element in the structuring of these arguments. Finally, some considerations for future implementations of Lesson Study cycles are proposed.