  In this paper, we analyze an aid session tested by an elementary school
teachers. This aid session has been set up by a teacher for some students with
difficulties after the work in the whole class. We first show how this aid
session can help the pupils, especially through its chrono-topo-meso-genetic
functions. Then we analyze a second situation in which the aid session is
implemented, looking for clues of these functions in some episodes involving
students who participated in the aid session.
