Thomas Cook, a pioneer of controlled experiments in education at Northwestern University, in Chicago, suggests that much of the opposition to experimental evaluation stems from a common philosophical malaise among social scientists, who doubt the validity of the natural sciences, and therefore reject the potential of knowledge derived from controlled experiments.

ECONOMIST: Social science: Try it and see | The

In its evaluation, IARC considers experimental evidence of carcinogenicity but gives priority to human epidemiologic evidence.

FORBES: How Activism Distorts The Assessment Of Health Risks