Our study focuses on knowledge texts (oral and written) produced in a regular sequence (in fourth grade class) and two "forced" sequences (in eighth and twelfth grade classes) in the magmatism area and their relationship with the text-working teaching practices. It aims to identify difficulties and didactic conditions of access to knowledge and problematized texts. We rely on both tools borrowed from the theoretical framework of problematization, the anthropological theory of didactics (ATD) and professional didactics to model and understand text-working teaching practices. It appears that problematized text-working presents technical difficulties due to teaching practices focused on identifying and sorting solutions in order to determine the right one for the problem. These techniques seem justified by technologies marked by the epistemological and didactic conceptions of teachers and the usual form of scientific knowledge at school. In contrast, the construction of knowledge and problematized texts requires of teaching actions leading to leaps of abstraction, allowing students to move from ideas to the reasons underlying the solutions. From a problematization logic, we identify some conditions for these text-working techniques to lead to the construction of problematized and non-propositional texts.
