PRINCIPLES OF UNCERTAINTY - WHAT ARE THEY - WHY DO WE NEED THEM

The meaning and utility of three principles of uncertainty is discussed. These principles, which are referred to as a principle of minimum uncertainty, a principle of maximum uncertainty, and a principle of uncertainty invariance, depend on the theory in which uncertainty is conceptualized. Due to a connection between uncertainty and information, the principles may also be conceived as principles of information. To make the principles operational in a particular uncertainty theory, we need to measure the amount of relevant uncertainty (and associated information) in each problem situation describable within the theory. Well-justified measures of uncertainty have thus far been established only in some uncertainty theories. These theories, their uncertainty measures, and the associated uncertainty principles are overviewed in the paper.