Positive

From Hobson's Choice

Desired as a means to some other end. Usually contrasted with normative.

In the social sciences, "positive" means that the researcher is withholding value judgments. In "positive economics," economists do not evaluate the realism of a theory's premises, but only if the theory produces accurate results.

The ultimate goal of a positive science is the development of theory” or “hypothesis” that yields valid and meaningful (i.e., not truistic) predictions about phenomena not yet observed. Such a theory is, in general, a complex intermixture of two elements. In part, it is a "language" designed to promote "systematic and organized methods of reasoning." In part, it is a body of substantive hypotheses designed to abstract essential features of complex reality... Viewed as a body of substantive hypotheses, theory is to be judged by its predictive power for the class of phenomena which it is intended to "explain." Only factual evidence can show whether it is “right” or "wrong" or, better, tentatively "accepted" as valid or "rejected." As I shall argue at greater length below, the only relevant test of the validity of a hypothesis is comparison of its predictions with experience. The hypothesis is rejected if its predictions are contradicted ("frequently" or more often than predictions from an alternative hypothesis); it is accepted if its predictions are not contradicted; great confidence is attached to it if it has survived many opportunities for contradiction. Factual evidence can never "prove" a hypothesis; it can only fail to disprove it, which is what we generally mean when we say, somewhat inexactly, that the hypothesis has been 'confirmed" by experience.
Milton Friedman, Essays on Positive Economics, Univ. of Chicago Press (1953), p.8

A criticism of this position is that it seeks to impose a spurious scientific legitimacy on economics by data mining. A hypothesis constructed from stylized facts has no valid predictive powers, since it merely assumes the future will have the same statistical attributes as a randomly selected period from the past. This is known as a fallacy of composition.

See Also

Positive-Normative Paradox

James R MacLean (19:52, 9 September 2007 (PDT))