Donald T. Campbell was a psychologist in the heyday of the 1970s. During this time, the belief emerged that society was a social engineering project that could be planned and evaluated. The general idea was that if you collected enough data, you could plan and control social change in a way that led to desired results. Economists from USAID believed this about economic development, military planners in Vietnam believed it, and Sociologists in the War on Poverty believed it. …