[Primary prevention in the school environment]

School failure are massive and related to social class. This situation requires a new conceptual and methodological frame. Indeed, more and more studies are unable to explain psychopathologically or sociologically on individual or familial cultural characteristics. Short term interventions require to take into account pedagogical and institutional mechanisms which convert cultural differences into school failures. In particualr, evaluation criteria utilised in de testing school inadaptation or to controle knowledge, play an important selective role. Among other interventions aimed maximising the educational process, realised in a national research, the author presents an attempt in mastery learning applied to fundamental education in first class. In this prespective, all children are asked to perform well defined operational objectives. The formative evaluation (as opposed to the normative evaluation) is totally integrated in effects of schooling. This type of intervention is not presented as a "model", but as a possibility to limit school failure. The mastery learning is one of the strategies which could be invested in a more global project where primary prevention and real democratisation of education would be simultaneously conceptualised.