First Advisor

Thomas Kindermann

Date of Publication


Document Type


Degree Name

Doctor of Philosophy (Ph.D.) in Systems Science: Psychology


Systems Science




Cognitive psychology, Bayesian statistical decision theory, Decision making -- Psychological aspects



Physical Description

1 online resource (xii, 225 p.) : ill. (some col.)


This study attempted to replicate and extend the study of Doherty, Mynatt, Tweney, and Schiavo (1979), which introduced what is here called the Bayesian conditionals selection paradigm. The present study used this paradigm (and a script similar to that used by Doherty et al.) to explore confirmation bias and related errors that can appear in both search and integration in probability revision. Despite selection differences and weak manipulations, this study provided information relevant to four important questions. First, by asking participants to estimate the values of the conditional probabilities they did not learn, this study was able to examine the use of "intuitive conditionals". This study found evidence that participants used intuitive conditionals and that their intuitive conditionals were affected by the size of the actual conditionals. Second, by examining both phases in the same study, this study became the first to look for inter-phase interactions. A strong correlation was found between the use of focal search strategies and focal integration strategies (r=.81, p


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Portland State University. Systems Science Ph. D. Program

Persistent Identifier