Résumé
Considering the context of rural NE Brazil, the purpose of this paper is to identify, to describe and to analyse the relations between two important elements that characterise the changes in course in a group of neighbouring communities in the Cariri region: social and technical innovation in the communities, and the forms of "external" institutional support for these processes. To do this, the paper considers the relationships between local social structures (including the community structures and organisations such as community associations and Unions) and innovations present in the field. Considering a time span of about 80 years, important changes in the configuration of these communities have occurred. The work of a sustainable development oriented NGO recently added itself to the influence of other traditional "external" actors, such as local political factions. The paper shows how these different initiatives work, identifying mis-understandings and interesting questions for debate. (Résumé d'auteur)