Do We Need Higher-Order Probabilities and, If So, What Do They Mean?

Abstract

The apparent failure of individual probabilistic expressions to distinguish uncertainty about truths from uncertainty about probabilistic assessments have prompted researchers to seek formalisms where the two types of uncertainties are given notational distinction. This paper demonstrates that the desired distinction is already a built-in feature of classical probabilistic models, thus, specialized notations are unnecessary.

Appears in Proceedings of the Third Conference on Uncertainty in Artificial Intelligence (UAI1987)