The terminal inefficiency of students in science careers among many universities around the world is a generalized problem. In the Science Faculty of the Morelos State University this issue is no different. There’s a high failure rate, above all, in the diverse Mathematics subjects. With the intention of improving this situation, a pilot plan in Geometry 1 for first year students has been set, which program is based on the ideas of J. Dieudonné, who suggests introducing concepts and axioms in an intuitive manner as a result of an experiment. The plan consisted on the intervention of a mediator, in a formative sense, who in a first stage makes observations of the second order (Arnold, M. 2003), with the purpose of registering the actions and interactions between teachers-students and students themselves. In a second stage, analyze both the registers of the observations from a micro-ethnographic perspective, in order to focus on the patterns of interaction to determine how this micro-processes are related with problems of a dispositional order (cognitive, affective and of sense) of the students; or with the problems of didactical-pedagogical order of the teacher. Along with this, it has been searched, from the standpoint of symbolic interactionism, to detect how the processes of distinctions of the observator and the teacher are interpreted by the former to re-direct her act’s and transform the ways in which she organizes his lines of action.