Sample size weighting in probabilistic inference

How do people evaluate data on the basis of sample size? Normatively, sample size is an important factor that one should consider when making judgments and inferences from sample data. Previous research is mixed regarding whether or not laypeople are sensitive to sample size. However, in this paper I show that laypeople attend to sample size, but that their sensitivity decreases as sample sizes become larger. This curvilinear functional form is found for both high and low numerate subjects across two different judgment tasks. However, high numerate subjects consistently show greater sensitivity to sample sizes than lower numerates, although they still underweight sample size relative to normative standards. Low numerate subjects’ sensitivity to sample size may be increased by providing raw data and instructions that sample size matters.Ph.D.Includes bibliographical referencesIncludes vitaby Natalie Ann Lindeman