THE BASE RATE FALLACY RECONSIDERED: DESCRIPTIVE, NORMATIVE AND METHODOLOGICAL CHALLENGES


Authors: 
Jonathan J. Koehler
Volume: 
19 (1)
Pages: 
online
Year: 
1996
Publisher: 
Behavioral and brain sciences
URL: 
http://www.bbsonline.org/documents/a/00/00/05/31/bbs00000531-00/bbs.koehler.html
Abstract: 

We have been oversold on the base rate fallacy in probabilistic judgment from an empirical, normative, and methodological standpoint. First, contrary to the conventional wisdom, a thorough examination of the literature reveals that base rates are almost always used and that their degree of use depends on task structure and internal task representation. Second, few tasks map unambiguously into the simple, narrow framework that is held up as the standard of good decision making. Third, the current approach is criticized for its failure to consider how the ambiguous, unreliable and unstable base rates of the real world should be used in the informationally rich and criterion-complex natural environment. A more ecologically valid research program is called for.

The CAUSE Research Group is supported in part by a member initiative grant from the American Statistical Association’s Section on Statistics and Data Science Education