Résumé
In the last years in Brazil, beside External Audit firm Certification (EAC), various participative certification instruments, behind the figure of Social Control certification, have been set up between producers or between producers and consumers. These alternatives are due to the development of local agro-ecological markets and the dynamics of the effects of reputation. This paper propose a comparative analysis of three certification systems (EAC, Network Participative Certification – NPC and Social Control Certification - OCS) in which the advantages and limitations of auto-centered and decentralized certification are highlighted as an autonomy process both for family farmers and consumers units and organizations. The first hypothesis of this paper is that a qualification process can contribute to establish a binary symmetrical relation of reciprocity between producer and buyer. It can also contribute to generate a sharing structure (of quality) among the group of producers. The second hypothesis is that Brazilian social movement's experiences in participatory certification (such co-certification, social group certification and participative certification systems) have mainly influenced the recent public policy tools established both by Ministry of Agriculture and Ministry of Agrarian Development. These two hypotheses are further developed, on the base of three study cases in Brazil. (Résumé d'auteur)