ERIC Number: EJ757911
Record Type: Journal
Publication Date: 2007-Jun
Pages: 21
Abstractor: Author
ISBN: N/A
ISSN: ISSN-0010-0277
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Waiting for the Bus: When Base-Rates Refuse to Be Neglected
Teigen, Karl Halvor; Keren, Gideon
Cognition, v103 n3 p337-357 Jun 2007
The paper reports the results from 16 versions of a simple probability estimation task, where probability estimates derived from base-rate information have to be modified by case knowledge. In the bus problem [adapted from Falk, R., Lipson, A., & Konold, C. (1994), the ups and downs of the hope function in a fruitless search. In G. Wright & P. Ayton (Eds.), "Subjective probability" (pp. 353-377). Chichester, UK: Wiley], a passenger waits for a bus that departs before schedule in 10% of the cases, and is more than 10 min delayed in another 10%. What are Fred's chances of catching the bus on a day when he arrives on time and waits for 10 min? Most respondents think his probability is 10%, or 90%, instead of 50%, which is the correct answer. The experiments demonstrate the difficulties people have in replacing the original three-category 1/8/1 partitioning with a normalized, binary partitioning, where the middle category is discarded. In contrast with typical studies of "base-rate neglect", or under-weighing of base-rates, this task demonstrates a reversed base-rate fallacy, where frequentistic information is overextended and case information ignored. Possible explanations for this robust phenomenon are briefly discussed.
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Publication Type: Journal Articles; Reports - Evaluative
Education Level: N/A
Audience: N/A
Language: English
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