Design researchers’ documentational genesis in a study on equivalence of algebraic expressions

While documentation work is at the core of teachers’ professional activity and professional development, this article argues for and illustrates the way in which documentation work is also central to the professional activity of design researchers. It has the double aim of contributing both to the documentational approach of didactics as well as to the literature on the teaching and learning of equivalence of algebraic expressions. The construct of documentational genesis, a component of the documentational approach of didactics as framed by Gueudet and Trouche (71:199–218, 2009), is extended to the processes of documentation work by design researchers and the production of three documents within the present study. The initial document is designed for secondary school mathematics on the topic of equivalence of algebraic expressions using CAS tools. Subsequent analysis of the classroom work involving the use of the designed activity sequence led to the generation of a follow-up complementary document on the domain-related theoretical underpinnings of algebraic equivalence. The third document is this research paper itself, which offers a description of the documentational genesis processes as well as the products thereby generated.