A Representation of Uncertainty to Aid Insight into Decision Models
  Many real world models can be characterized as weak, meaning that there is
significant uncertainty in both the data input and inferences. This lack of
determinism makes it especially difficult for users of computer decision aids
to understand and have confidence in the models. This paper presents a
representation for uncertainty and utilities that serves as a framework for
graphical summary and computer-generated explanation of decision models. The
application described that tests the methodology is a computer decision aid
designed to enhance the clinician-patient consultation process for patients
with angina (chest pain due to lack of blood flow to the heart muscle). The
angina model is represented as a Bayesian decision network. Additionally, the
probabilities and utilities are treated as random variables with probability
distributions on their range of possible values. The initial distributions
represent information on all patients with anginal symptoms, and the approach
allows for rapid tailoring to more patientspecific distributions. This
framework provides a metric for judging the importance of each variable in the
model dynamically.
