This article describes an integration of most of the disparate likelihood j
udgment phenomena in behavioral decision making using a mathematical memory
model. A new theory of likelihood judgments based on D. L. Hintzman's (198
4, 1988) MINERVA2 memory model is described. The model, MINERVA-DM (DM = de
cision making), accounts for a wide range of likelihood judgment phenomena
including frequency judgments, conditional likelihood judgments, conservati
sm, the availability and representativeness heuristics, base-rate neglect,
the conjunction error, the validity effect, the simulation heuristic, and t
he hindsight bias. In addition, the authors extend the model to expert prob
ability judgment and show how MINERVA-DM can account for both good and poor
calibration (overconfidence) as a function of varying degrees of expertise
. The authors' work is presented as a case study of the advantages of apply
ing memory theory to study decision making.