Through an analysis of the pedagogic practices, this paper aims at demonstrating the changes in the educational system in the French secondary education. Exploring the educational action developed in (private and public) secondary schools of the city of Lille (northern France) reveals that these are highly rated both because of the results of their pupils at the baccalauréat (final examination) and their tendency to prepare their best pupils for the "high schools". Since they prepare the leading elites of the public and private sector, these hold a significant place in the French higher education system. This investigation highlights the differences that arise within the classes as a function of the kind of pedagogy used by teachers according to their judgments or appreciations on the future of their pupils. Although the contents are the same for all pupils, their transmission modalities differ and some succeed in acquiring knowledge in a "rational" way while others receive it through educational "experiments" that do not allow them to perceive the discipline logic or principles.
Secondary education; Educational action; Transmission of knowledge; Rational pedagogy; Pedagogical experimentation