The intuitive conceptualization and perception of variance.

ABSTRACT

Statistical concepts (e.g., mean, variance, correlation) offer powerful ways to characterize the structure of the environment. To what extent do statistical concepts also play a role for people assessing the environment? Previous work on the mind as "intuitive statistician" has mainly focused on the judgment of means and correlations (Peterson & Beach, 1967). Much less is known about how people conceptualize and judge variance. In a survey and three experimental studies, we explored people's intuitive understanding of variance as a concept and investigated the factors affecting people's judgments of variance. The survey findings showed that most people hold concepts of variance that they can articulate; these concepts, however, reflect not only statistical variance (i.e., deviations from the average) but also the pairwise distance between stimuli, their range, and their variety. The experimental studies revealed that although people's judgments of variance are sensitive to the statistical variance of stimuli, variety and range also play an important role. The results can inform psychological models of judgments of variance.