**Abstract**

This text briefly presents two PhDs achieved as part of a larger research project led by the team in mathematics didactics in Geneva on mathematical problem-solving at different school levels. The first PhD, by Maud Chanudet, examines teachers' assessment practices in the context of a mathematics problem-solving course offered at a lower secondary level in Geneva. The second PhD, by Stéphane Favier, aims to document the work of students at different school levels (primary and lower secondary) in problem-solving situations, through detailed analyses of students' work and interactions with each other and with the teacher. These two studies revealed ways to help teachers support students' problem-solving activities. This led us to set up a collaborative project with teachers to study two complementary processes—devolution and institutionalization—with a view to developing a training resource. We'll briefly introduce this new stage of our research.

**Keywords:** problem solving, assessment practices, heuristics, teacher regulation, collaborative research
