A historical perspective on the use of randomized trials in social sciencesettings

Similar to medicine, social science has historically grappled with controll ing for chance and bias in assessing the effectiveness of interventions. Qu estions about what works and how to evaluate the evidence underlie all area s of policy intervention. In the early years of the 20th century, social sc ience in North America developed an established tradition of quantitative s ociology that included experimental studies. This was followed by a number of social experiments from the 1960s to the 1980s. The history of prospecti ve experimental studies with control groups applied to the social domain co ntains important lessons for experimental social science in the 21st centur y.