ABSTRACT
But in the social sciences there are no equally valid tests and checks. An inquiry into the merits of some political, economic, or educational method or device, P.R., profit-sharing, prohibition, Montessori teaching, vaccination, indeterminate sentences, is liable to be vitiated at every step by selection, mis-valuation, or doping of evidence, due to the presence of
a desire to prove a case, and the difficulty of conviction for error. Where deeply engrained habits of thought and sentiment are involved, as in the support or rejection of political, economic, or other social opinions on matters of urgency, an unlimited amount of such bias is likely to enter a professedly ‘scientific’ inquiry.
