Classical (Bayesian) probability (CP) theory has led to an influential research tradition for
modeling cognitive processes. Cognitive scientists have been trained to work with CP
principles for so long that it is hard even to imagine alternative ways to formalize …

We present a novel variant of decision making based on the mathematical theory of
separable Hilbert spaces. This mathematical structure captures the effect of superposition of
composite prospects, including many incorporated intentions, which allows us to describe a …

Probability theory has long been taken as the self-evident norm against which to evaluate
inductive reasoning, and classical demonstrations of violations of this norm include the
conjunction error and base-rate neglect. Many of these phenomena require multiplicative …

In the present article we consider the conjunction fallacy, a well known cognitive fallacy
experimentally tested in cognitive science, which occurs for intuitive judgments. We show
that the quantum formalism can be used to describe, in a very simple way, this fallacy, in …

The conjunction fallacy has been a key topic in debates on the rationality of human
reasoning and its limitations. Despite extensive inquiry, however, the attempt to provide a
satisfactory account of the phenomenon has proved challenging. Here we elaborate the …

Errors in probabilistic reasoning have been the focus of much psychology research and are
among the original topics of modern behavioral economics. This chapter reviews theory and
evidence on this topic, with the goal of facilitating more systematic study of belief biases and …

Two experiments used within-subject designs to examine how conjunction errors depend on
the use of (1) choice versus estimation tasks,(2) probability versus frequency language, and
(3) conjunctions of two likely events versus conjunctions of likely and unlikely events. All …

Alternative measures of confirmation or evidential support have been proposed to express
the impact of ascertaining one event on the credibility of another. We report an experiment
that compares the adequacy of several such measures as descriptions of confirmation …

The systematic biases seen in people's probability judgments are typically taken as
evidence that people do not use the rules of probability theory when reasoning about
probability but instead use heuristics, which sometimes yield reasonable judgments and …

Major recent interpretations of the conjunction fallacy postulate that people assess the
probability of a conjunction according to (non-normative) averaging rules as applied to the
constituents' probabilities or represent the conjunction fallacy as an effect of random error in …