This paper, which results from a lecture given at NORMA08, proposes a reflection on
the idea of didactical design, using the notion of didactical engineering as a
specific lens. It is structured into three parts. In the first and introductory part, we
point out the increasing attention paid to design issues in mathematics education,
and some of its internal and external sources. In the second and main part, we come
to the notion of didactical engineering analyzing its emergence in French didactical
research, its development from the early eighties until now, and its influence on
didactical design at large. In the third part, we extend the reflection by considering
the way design issues are approached in the anthropological theory of didactics.