Published online by Cambridge University Press: 01 December 1997
Koehler's (1996t) target article raised, and various commentators discussed, two issues that seem far separated but actually have a great deal in common. These are the value of “ecologically valid” research and the effect of direct experience on base-rate usage. Koehler discussed the former as a methodological issue and the latter as a normative one, and no commentator chose to incorporate them, but directly experienced base rates are a good example of ecologically valid research. The state of the literature with regard to directly experienced base rates is reviewed, and the emerging perception, that direct experience has a profound Bayesian effect on base-rate usage, is rejected.