2 Facets of Generalized U ncertainty-based Information

Review of current research on broad concepts of uncertainty and infor­ mation that is based on uncertainty reduction. A formalization of these concepts is conceived, in general, within a broad framework consisting of fuzzy set theory and fuzzy measure theory. This framework is sufficiently general to capture virtually all conceivable types of uncertainty via appropriate uncertainty theories. Three levels are distinguished in each uncertainty theory: uncertainty formalization, uncertainty measurement, and uncertainty utilization. Thus far, uncertainty (and uncertainty­ based information) has been investigated at each of these three levels only in the Dempster-Shafer theory of evidence and its special branches. Results of these in­ vestigations are reviewed.