Abstract
Many efforts to use the social sciences for the purpose of change and reconstruction have their roots in the idea of the field experiment. In various forms, the field experiment played a dominant role in the period 1930-1970. In more recent years, new patterns have emerged, such as complementary research roles in network building. In this contribution, focus is on the links between the early experiments and today's approaches, to see the latter in terms of responses to the challenges posed by the processes that were triggered off by the field experiments.