In decisions under uncertainty is understood in the decision theory situations where the occurrence of future environmental conditions can not be predicted with certainty. That is, the effect of selecting one of the alternatives available are not fully known. In contrast, the decisions are under security.
Although still not a unified language has evolved, so different Müller ( 1993), depending on whether the probabilities for the environmental conditions are known, between:
Frank Knight ( 1921) distinguishes in his book, Risk, Uncertainty and Profit ' further escalation stage of insecurity:
In decision theory, numerous methods have been developed in order to apply appropriate decision rules, despite the uncertainty can (min -max, max -min, expected value, ...).