ABSTRACT
This chapter describes the evolution of a field of research and investigates cognitive and social aspects of mathematics learning. It presents the progressive modification of the issue under study. In the late 1970s chapter immerses in the study of the role of social factors in development, bringing to the fore the role of interpersonal interactions as providing the driving force behind cognitive development. At that time people's institutional involvement in a department of educational sciences and people's pedagogical concerns induced them to deal more precisely with learning tasks that were meaningful in the school context and hence different from those usually implemented in the studies of the mechanisms of thought in general. From a methodological point of view, the studies mark transition from an approach centred on effects of certain interactions to one focusing on the processes put into action by those interacting in order to make sense of the task and of the situation into which they are thrown.
