Exploring the overestimation of conjunctive probabilities

Nilsson, Håkan and Rieskamp, Jörg and Jenny, Mirjam A.. (2013) Exploring the overestimation of conjunctive probabilities. Frontiers in Psychology, Vol. 4 , 101.

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Official URL: http://edoc.unibas.ch/dok/A6124595

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People often overestimate probabilities of conjunctive events. The authors explored whether the accuracy of conjunctive probability estimates can be improved by increased experience with relevant constituent events and by using memory aids. The first experiment showed that increased experience with constituent events increased the correlation between the estimated and the objective conjunctive probabilities, but that it did not reduce overestimation of conjunctive probabilities. The second experiment showed that reducing cognitive load with memory aids for the constituent probabilities led to improved estimates of the conjunctive probabilities and to decreased overestimation of conjunctive probabilities. To explain the cognitive process underlying people's probability estimates, the configural weighted average model was tested against the normative multiplicative model. The configural weighted average model generates conjunctive probabilities that systematically overestimate objective probabilities although the generated probabilities still correlate strongly with the objective probabilities. For the majority of participants this model was better than the multiplicative model in predicting the probability estimates. However, when memory aids were provided, the predictive accuracy of the multiplicative model increased. In sum, memory tools can improve people's conjunctive probability estimates.
Faculties and Departments:07 Faculty of Psychology > Departement Psychologie > Forschungsbereich Sozial-, Wirtschafts- und Entscheidungspsychologie > Economic Psychology (Rieskamp)
UniBasel Contributors:Rieskamp, Jörg
Item Type:Article, refereed
Article Subtype:Research Article
Note:Publication type according to Uni Basel Research Database: Journal article
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Last Modified:25 Oct 2013 08:33
Deposited On:25 Oct 2013 08:33

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