Once people know the outcome of an event, they tend to overestimate what could have been anticipated in foresight. Although typically considered to be a robust phenomenon, this hindsight bias is subject to moderating circumstances. In tbeir meta-analysis, Christensen-Szalanski and Willham (1991) observed that tbe more experience people have with tbe task under consideration, the smaller is the resulting hindsigbt bias. This observation is one benchmark against wbicb tbe explanatory power of

more »

... ess models of bindsight bias can be measured. Therefore, we used it to put the recently proposed RAff model (Hoffrage, Hertwig, & Gigerenzer, 2000) to another test. Our findings were consistent witb the "expertise effect." Specifically, we observed-using computer simulations of the RAff model-that the more comprehensive people's knowledge is in foresigbt, the smaller is their hindsight bias. In addition, we made two counterintuitive observations: First, the relation between foresight knowledge and hindsight bias appears to be independent of how knowledge is processed. Second, even if foresight knowledge is false, it can reduce hindsight bias. We conclude with a discussion of the functional value of hindsight bias. Requests für reprints shouJd be sent to Ralph