Content Analysis of Cognitive Bias: Development of a Standardized Measure

Abstract

The purpose of this research was to develop a standardized content analytic measure of cognitive bias as conceptualized in Beck's (1987) cognitive theory of depression. In a pilot study it was determined that a written stimulus format was preferable to an audiotaped stimulus format with respect to comprehensibility. Valence and expectancy ratings collected in this pilot study also served as the basis for selection of items for the final measure, balancing positive and negative, expected and unexpected events. In study 2 open-ended written responses to questions about the main cause of each event, and the justifications for these attributions, were coded for indices of bias, defined (as in Cook & Peterson, 1986) as justifications that fail to cite covariation of the ascribed cause with the effect. Cognitive bias scores in Study 2 showed internal consistency (positive item-remainder correlations) and high interrater reliability. As predicted, justifications of attributions for expected events were more biased and less rational than were justifications of attributions for unexpected events.