Accession Number : ADA099502


Title :   Judgments of and by Representativeness


Descriptive Note : Technical rept. Jan 1980-Apr 1981


Corporate Author : STANFORD UNIV CA DEPT OF PSYCHOLOGY


Personal Author(s) : Tversky, Amos ; Kahneman, Daniel


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a099502.pdf


Report Date : 15 May 1981


Pagination or Media Count : 37


Abstract : The concept of representativeness and the conditions in which it can be used to explain intuitive predictions and probability judgments are discussed. Four cases of representativeness are distinguished that refer to the relations between a value and a variable; an instance and a category; a sample and a population; an effect and a cause. The principles of representativeness differ significantly from the laws of probability. In particular, specificity can increase the representativeness of an event, even though it always reduces its probability. Several studies of judgment are reported in which naive and sophisticated respondents judge a conjunction to be more probable than one of its components. Violations of the conjunction rule. P(A&B) P(B), are observed in both between-subjects and within-subjects comparisons, with both fictitious and real-world events. The theoretical and practical implications of the conjunction fallacy are explored.


Descriptors :   *JUDGEMENT(PSYCHOLOGY) , PREDICTIONS , PROBABILITY


Subject Categories : Psychology


Distribution Statement : APPROVED FOR PUBLIC RELEASE