Subjective Probabilities: Overview

Abstract

Abstract The need for subjective probabilities arises from the variability that is pervasive in our world. A subjective probability is intended to meaningfully communicate the degree of uncertainty in the face of variability. Surrounding this common theme are several different approaches to defining and using subjective probabilities. The mathematical theory of probability is summarized as a basis for understanding these approaches. This article then describes the alternative perspectives on subjective probability relative to the mathematical theory: subjective probability as one of several interpretations for mathematical probability theory, as a behavioral assessment, as an inherent aspect of all uses of probability theory, and as an uncertainty measure that can be detached from the mathematical theory. The issue of assessing the quality of subjective probabilities is also discussed as it relates to these approaches.