Aggregation bias in estimates of perceptual agreement.

Abstract : It is shown that estimates of agreement based on group mean scores have been incorrectly interpreted as applying to perceptual agreement among individuals. Of initial importance is a study by Drexler (1977), who concluded that a considerable proportion of the variance in climate perceptions is accounted for by organizational membership. This conclusion has been employed recently by other authors to support the assumption that individuals in the same environment tend to agree with respect to climate perceptions. The present paper demonstrates that Drexler's analysis provided inflated estimates of agreement among individuals. The logic of the approach is then extended to other studies in which inflated estimates of agreement appeared likely. (Author)