Naive empiricism and dogmatism in confidence research: A critical examination of the hard-easy effect

Two robust phenomena in research on confidence in one's general knowledge a re the overconfidence phenomenon and the hard-easy effect. In this article, the authors propose that the hard-easy effect has been interpreted with in sufficient attention to the scale-end effects, the linear dependency, and t he regression effects in data and that the continued adherence to the idea of a "cognitive overconfidence bias" is mediated by selective attention to particular data sets. A quantitative review of studies with 2-alternative g eneral knowledge items demonstrates that, contrary to widespread belief, th ere is (a) very little support for a cognitive-processing bias in these dat a; (b) a difference between representative and selected item samples that i s not reducible to the difference in difficulty; and (c) near elimination o f the hard-easy effect when there is control for scale-end effects and line ar dependency.