Considering the Law of Inclusion (20.845/2015), which promotes social mixture of Chilean students, this research studies a subsidized school in a context of poverty that has promoted this mixture since its creation in 1980, being free and without selection. We seek to understand how do the social inclusion/exclusion processes of children deploy in this marginalized scene. What means then “to include”? Which are the frontiers between inclusion and exclusion in this school? We realized an interpretative school ethnography for 7 months, with a focus on a 4th grade. The first results in the field are centered on the micro-politics of the school (Ball, 1987). We identify three principal dispositives: an identity dispositive that lies on the historical ethos of the school and its social inclusion project; a traditional dispositive, which reflects the cultural trajectories of the subjects and the representations presents in society; a technocratic dispositive that is gradually installed from the educative system looking for the standardization of the educative process. During the research process, we observe the evolution of the equilibrium between the three dispositives in the school, where the ethical finalities of inclusion are overcome by the technocratic objectives of standardization. We present cooperative pedagogical practices existing in the school that disappear to the benefit of classification technologies and competitive strategies.