Framing effects in judgment tasks with varying amounts of information

Subjects were asked to make evaluations in each of three tasks—a gambling task, a consumer judgment task, and a student evaluation task. Each task involved two important attributes, but information about one attribute was missing on some trials. Half of the subjects received a version of the task in which a key attribute was presented in positive terms (e.g., probability of winning a gamble) and half received a version in which that same attribute was presented in negative terms (e.g., probability of losing a gamble). Even though the information was objectively equivalent in the two versions of each task, there were two significant framing effects. (1) In all tasks, responses to two-attribute stimuli were more favorable in the positive condition than in the negative condition. (2) When the key attribute was missing, evaluations of one-attribute stimuli relative to evaluations of two-attribute stimuli were lower in the positive condition than in the negative condition. Results were discussed in terms of the constructs of prospect theory and information integration theory.     

The allure of equality: uniformity in probabilistic and statistical judgment

Uniformity, that is, equiprobability of all available options is central as a theoretical presupposition and as a computational tool in probability theory. It is justified only when applied to an appropriate sample space. In five studies, we posed diversified problems that called for unequal probabilities or weights to be assigned to the given units. The predominant response was choice of equal probabilities and weights. Many participants failed the task of partitioning the possibilities into elements that justify uniformity. The uniformity fallacy proved compelling and robust across varied content areas, tasks, and cases in which the correct weights should either have been directly or inversely proportional to their respective values. Debiasing measures included presenting individualized and visual data and asking for extreme comparisons. The preference of uniformity obtains across several contexts. It seems to serve as an anchor also in mathematical and social judgments. People’s pervasive partiality for uniformity is explained as a quest for fairness and symmetry, and possibly in terms of expediency.     

Secondhand information and social judgment

This research investigates how secondhand impressions of other people differ from those based on firsthand information. It was hypothesized that secondhand impressions are often more extreme because secondhand accounts of another person's actions frequently fail to convey adequately the role of mitigating circumstances and situational constraints in producing that person's behavior. Experiments 1 and 2 tested this hypothesis by exposing “first generation” subjects to information about a target person, having them rate the target on several trait and attribution scales, and having them describe the target person's actions to a group of “second generation” subjects. As predicted, second generation subjects made more extreme ratings of the target than their first generation counterparts. Content analyses of the accounts transmitted by first generation subjects indicated that they did indeed underemphasize various situational qualifications of the target persons' behavior. Experiment 3 extended these findings by demonstrating that people's impressions of someone they have often heard about from a friend (but never met) are more extreme than their friends' more informed impressions.     

Causal judgment from contingency information: Relation between subjective reports and individual tendencies in judgment

In two experiments, participants made causal judgments from contingency information for problems with different objective contingencies. After the judgment task, the participants reported how their judgments had changed following each type of contingency information. Some reported idiosyncratic tendencies--in other words, tendencies contrary to those expected under associative-learning and normative rule induction models of contingency judgment. These idiosyncratic reports tended to be better predictors of the judgments of those who made them than did the models. The results are consistent with the view that causal judgment from contingency information is made, at least in part, by deliberative use of acquired and sometimes idiosyncratic notions of evidential value, the outcomes of which tend, in aggregate, to be highly correlated with the outcomes of normative procedures.     

Justification effects on the judgment of analogy

Many of us share a strong intuition that justification forces us to better understand the situations we face. And there is substantial evidence indicating that this is often the case. However, there is a growing body of research showing that, under certain circumstances, explanation and justification can impair performance on a variety of cognitive tasks. In the present research, the effects of justification on judgment of the soundness of analogies were examined. Subjects judged the quality of the match between pairs of stories with varying degrees of superficial and analogical similarity. Experimental subjects either provided reasons for their judgments or wrote recollections of the target stimuli. These subjects rated the match between stimulus pairs as more sound than did control subjects. Also, providing reasons led to poorer discrimination between superficially similar aspects of the stimuli and analogous aspects. Explanations of these findings are proposed, and implications for problem solving and confidence judgment are discussed.     

Estimating sample-size requirements in research design: A study of intuitive statistical judgment

Subjects were given an experimental task in which they had to play the role of a quality-control researcher for a company. They had to consider a hypothetical experiment that involves testing a sample of batteries from a truck load, which may or may not be substandard. In the main experiment, subjects were given information about the prior probability of substandard truck loads (base rate), the degree of variability of battery life, and the mean difference between standard and substandard batteries, all of which are formally relevant to the decision, and they were also told the number of batteries in the truck (population size) that is formally irrelevant. The task was to decide (intuitively) how many batteries to test to achieve a specified error rate using a specified decision rule. In a second study, subjects were given a similar scenario, but asked to rate which pieces of information would be relevant to the decision. Subjects showed themselves to be sensitive to the effects of sample variability and base rate when making intuitive design decisions, though an odd effect of the mean difference factor was observed. There is also clear confirmation of a bias-to-weight sample size by population size as reported in earlier research using different kinds of judgmental tasks.     

Sequential effects in face-attractiveness judgment

A number of studies have shown that current-trial responses are biased toward the response of the preceding trial in perceptual decisionmaking tasks (the sequential effect-Holland and Lockhead, 1968 Perception & Psychophysics 3 409-414). The sequential effect has been widely observed in evaluation of the physical properties of stimuli as well as more complex properties. However, it is unclear whether subjective decisions (e.g., attractiveness judgments) are also susceptible to the sequential effect. Here, we examined whether the sequential effect would occur in face-attractiveness judgments. Forty-eight pictures of male and female faces were presented successively. Participants rated the attractiveness of each face on a 7-point scale. The results showed that the attractiveness rating of a given face assimilated toward the rating of the preceding trial. In a separate experiment, we provided the average attractiveness rating by others for each trial as feedback. The feedback weakened the sequential effect. These findings suggest that attractiveness judgment is also biased toward the preceding judgment, and hence the sequential effect can be extended into the domain of subjective decisionmaking.     

Contextual effects in social judgment

Judges were asked to evaluate the overall performance of hypothetical students, given their scores on two examinations. The distribution of total scores was manipulated in order to investigate the loci of contextual effects. The interaction between the two exams was reversed by manipulation of the distribution. When the distribution of total scores was positively skewed, judgments showed a convergent interaction as a function of the two exams; when the distribution was negatively skewed, the interaction was divergent. The data were consistent with the hypothesis that the distribution of total scores affects only the transformation from integrated impressions to overt responses. This transformation (judgment function) was well-described by an extension of range-frequency theory. The finding that the interaction can be manipulated by changing the stimulus distribution has methodological implications for the popular interpretation of interactions or lack thereof. A good model may be improperly rejected or a bad one improperly retained through lack of attention to contextual effects.     

Feature cues in probability learning: Data base information and judgment

Judgments of probabilistic events are often based partly on some information about past similar events. This study investigates the impact of summarized historical data termed a feature cue on performance in a cue probability learning task. Judges (n = 64) made 150 predictions of a criterion variable (Y_e) from a single cue variable (X). The feature cue variable (Z) provided judges with the “average past criterion” for the cue value on trial i, i.e., the conditional mean . Availability of the feature cue was varied with an AB-BA transfer design. Results demonstrate that the presence of the feature cue greatly imporved prediction achievement and accuracy. Under certain conditions, consistency and cue weighting were also improved by the feature cue aid. Although the feature cue value itself was not used as a prediction, it served as an anchor, around which judgments were dispersed. Implications for decision making with data base information are discussed.     

Causal judgment from contingency information: the interpretation of factors common to all instances

Participants made judgments about stimulus materials in which there were 2 possible causes of an outcome. One of these was a common factor, a factor present in all instances presented for judgment, and the other was a positive covariate of the outcome. Instead of interpreting the positive covariate as the cause, participants consistently preferred an interpretation in which the common factor was the cause and the positive covariate enabled the cause to produce its effect. Participants' judgments of both interpretations were predicted by the proportion of instances that were confirmatory for the interpretation and not by deltaP. The findings support a hypothesis that people have a multirole conceptualization of causality including, in addition to the roles of cause and effect, that of an enabler, a factor the presence of which ensures that a thing is in a state of readiness to produce a particular effect.     

Stereotypes and social judgment: the effects of typicality and group heterogeneity

Two experiments showed that when subjects believed a group to be heterogenous, they based their liking for a particular group member on their liking for the group as a whole, independently of and in addition to the target's behavior, and regardless of the target's typicality. When they believed the group to be homogenous, however, they treated the target's typicality as a favorable or unfavorable attribute, which affected their evaluation. The latter subjects used their group stereotype as a standard of comparison in judging the implications of the target's behavior for a trait to which it was relevant. All subjects' stereotypes had a positive influence on judgments of stereotyped-related traits for which the target's behavior was uninformative. A conceptualization is proposed to account for these findings.     

The influence of improper sets of information on judgment: how irrelevant information can bias judged probability

This article introduces 2 new sources of bias in probability judgment, discrimination failure and inhibition failure, which are conceptualized as arising from an interaction between error prone memory processes and a support theory like comparison process. Both sources of bias stem from the influence of irrelevant information on participants' probability judgments, but they postulate different mechanisms for how irrelevant information affects judgment. The authors used an adaptation of the proactive interference (PI) and release from PI paradigm to test the effect of irrelevant information on judgment. The results of 2 experiments support the discrimination failure account of the effect of PI on probability judgment. In addition, the authors show that 2 commonly used measures of judgment accuracy, absolute and relative accuracy, can be dissociated. The results have broad implications for theories of judgment.