title: No evidence for rule-based processing in the inverse base-rate effect.
abstract: The inverse base-rate effect in categorization (Medin & Edelson, 1988) arises when participants assign an ambiguous stimulus to a category that occurred less frequently than an alternative category, against the principles of Bayesian decision making. In the experiment reported in this article, rule-based and attention-shifting accounts of the inverse base-rate effect were evaluated. Participants completed a categorization task, known to produce the inverse base-rate effect, under standard conditions, under time pressure, and with a secondary task load. The inverse base-rate effect persisted under severe time pressure and under secondary task load. The results provided no evidence for the role of rule-based processes in producing the inverse base-rate effect. The data from the experiment are compatible with an attention-shifting account.
authors.affiliation: Department of Psychology, University of Warwick, Coventry, England. k.lamberts@warwick.ac.uk
authors.forename: Koen
authors.initials: K
authors.lastname: Lamberts
authors.forename: Christopher
authors.initials: C
authors.lastname: Kent
mesh_terms: D000293:Adolescent; D000328:Adult; D001143:Arousal; D001288:Attention; D001499:Bayes Theorem; D003657:Decision Making; D004193:Discrimination Learning; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual; D011340:Problem Solving; D014163:Transfer, Psychology