title: Base rates, contingencies, and prediction behavior.
abstract: A skew in the base rate of upcoming events can often provide a better cue for accurate predictions than a contingency between signals and events. The authors study prediction behavior and test people's sensitivity to both base rate and contingency; they also examine people's ability to compare the benefits of both for prediction. They formalize these notions and propose a new measure of the regularity in the environment (ExpPA). In two experiments they test whether the notions underlying this measure capture prediction behavior. In the first experiment, they compare participants' prediction behavior, preference, and assessment of contingencies in two data sets that differ only in their base rate. In the second, in which the contribution of contingency over base rate is manipulated, they study participants' willingness to forgo a costly predictor. Results indicate a close correspondence between ExpPA and behavior.
authors.affiliation: School of Education and Center for the Study of Rationality, Hebrew University of Jerusalem, Israel. kareev@vms.huji.ac.il
authors.forename: Yaakov
authors.initials: Y
authors.lastname: Kareev
authors.forename: Klaus
authors.initials: K
authors.lastname: Fiedler
authors.forename: Judith
authors.initials: J
authors.lastname: Avrahami
mesh_terms: D001245:Association Learning; D003118:Color Perception; D003463:Cues; D003469:Culture; D003657:Decision Making; D005544:Forecasting; D005715:Gambling / Q000523:psychology; D006801:Humans; D007600:Judgment; D009042:Motivation; D010364:Pattern Recognition, Visual; D011337:Probability Learning; D011340:Problem Solving; D012718:Set, Psychology