Anchoring in sequential judgments

Building on the scale distortion theory (Frederick & Mochon, 2012), we explore the boundary conditions of anchoring outside of the standard paradigm. We argue that the conditions needed for anchoring effects are much more restrictive than those suggested by some theories, but much less restrictive than those suggested by others. Our findings illuminate both the scope and limits of this well-known effect and provide a framework for predicting its occurrence in novel settings.     

A big fish or a small pond? Framing effects in percentages

This paper presents three studies that demonstrate people’s preference for a large percentage of a small subset over a small percentage of a large subset, when the net overall quantity is equated. Because the division of a set into subsets is often arbitrary, this preference represents a framing effect. The framing effect is particularly pronounced for large percentages. We propose that the effect has two causes: A partial neglect of the subset information, and a non-linear shaped function in the way people perceive percentages.     

Correcting Overestimated Effect Size Estimates in Multiple Trials

In a simulation study, Brand, Bradley, Best, and Stoica (2011 Brand, A., Bradley, M. T., Best, L. A. and Stoica, G. 2011. Multiple trials may yield exaggerated effect size estimates. The Journal of General Psychology, 138: 1–11. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) have shown that Cohen's d is notably overestimated if computed for data aggregated over multiple trials. Although the phenomenon is highly important for studies and meta-analyses of studies structurally similar to the simulated scenario, the authors do not comprehensively address how the problem could be handled. In this comment, we first suggest a corrective term d ^′ _c that includes the number and correlation of trials. Next, the results of a simulation study provide evidence that the proposed d_c′ results in a more precise estimation of trial-level effects. We conclude that, in practice, d ^′ _c together with plausible estimates of inter-trial correlation will produce a more precise effect size range compared to that suggested by Brand and colleagues (2011 Brand, A., Bradley, M. T., Best, L. A. and Stoica, G. 2011. Multiple trials may yield exaggerated effect size estimates. The Journal of General Psychology, 138: 1–11. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]).     

A Comprehensive Literature Review of the Rank Reversal Phenomenon in the Analytic Hierarchy Process

During the last few decades, several multi‐criteria decision analysis methods have been proposed to help in selecting the best compromise alternatives. Among them, analytic hierarchy process (AHP) and its applications have attracted much attention from academics and practitioners. However, since the early 1980s, critics have raised questions regarding its proper use. One of them concerns the unacceptable changes in the ranks of the alternatives, called rank reversal, upon changing the structure of the decision. Several modifications were suggested to preserve ranks. In this paper, a classification scheme and a comprehensive literature review are presented in order to uncover, classify and interpret the current research on AHP methodologies and rank reversals. On the basis of the scheme, 61 scholarly papers from 18 journals are categorized into specific areas. The specific areas include the papers on the topics of adding/deleting alternatives and the papers published in adding/deleting criteria. The scholarly papers are also classified by (1) year of publication, (2) journal of publication, (3) authors' geographic location and (4) using the AHP in association with other methods. It is hoped that the paper can meet the needs of researchers and practitioners for convenient references of AHP methodologies and rank reversals and hence promote the future of rank reversal research. Copyright © 2012 John Wiley & Sons, Ltd.     

Covariation assessment in rank order data

Two experiments were conducted to investigate how individuals assess covariation with rank order data. In both studies, subjects were given sets of rank order data, each set consisting of ten items ranked on two characteristics, and were asked to estimate the degree of relationship for each set. Contrary to previous research, subjects' estimates of covariation in this task were quite sensitive to actual levels of correlation in the data and remained unaffected by simple variations in the way rank order data were presented. More importantly, it appeared that this sensitivity to covariation was due likely to the use of a simple heuristic referred to here as the total discrepancy heuristic. These findings are discussed in terms of the availability of simple heuristics in rank-ordered versus other types of data and the consequences of using such heuristics in decision-making contexts.     

Levels of aggregation: Relative time allocation in concurrent-schedule performance

The proportion of time allocated to one component of a concurrent variable-interval variable-interval schedule was computed for groups of interchangeover times (aggregates) within several intact time series. Variability in obtained proportions decreased as the number of interchangeover times within each aggregate increased; however, modal proportions failed to correspond to overall relative time allocation computed over the course of an entire experimental session, even at the largest aggregate size. The aggregated time series showed periodicities at small aggregate sizes and general trends in local preference at larger aggregate sizes. It is suggested that overall relative time allocation represents a molar extreme in the aggregation of behavior that may not accurately reflect central tendency in the allocation of time to available alternatives within the context of ongoing behavior.     

The need for contextual and technical knowledge in judgmental forecasting

The purpose of this research is to assess the extent to which judgmental forecasts are improved by having more contextual and technical knowledge. Contextual information is knowledge gained by practitioners through experience on the job, consisting of general forecasting experience in the industry as well as specific product knowledge. Technical knowledge is knowledge about data analysis and formal forecasting procedures, including information on how to analyze data judgmentally. We directly compared judgmental forecasts of business practitioners with those generated by students, using 22 real-world time series. The practitioners had considerable contextual but no technical knowledge. The students had no contextual but two different levels of technical knowledge. We also generated forecasts with statistical methods to benchmark performance. Results show that contextual knowledge is particularly important in making good judgmental forecasts, while technical knowledge has little value. Practitioner forecasts are better than student forecasts in almost all comparisons. A decisive factor affecting forecast performance appears to be data variability, measured by the coefficient of variation of the time-series data. As the variability of a time series increases, the performance of all forecasts deteriorates, but judgmental forecasts by practitioners become more preferable. Statistical methods have difficulty achieving reasonable forecasts when the data are more variable, whereas judgemental forecasts reinforced by contextual information do relatively well. Data variability is one explanation for the mixed findings of past studies, relative to how well statistical techniques compare with judgment as a forecasting method.     

Familial Aggregation of ADHD Characteristics

Patterns of familial aggregation of ADHD symptoms in parents of ADHD and non-ADHD children were examined. Within the ADHD sample, symptom aggregation was examined as a function of biological relationship, parent and child gender, and children's comorbid diagnoses. Participants consisted of parents of 579 children with ADHD, Combined Type participating in the multimodal treatment study of children with ADHD and parents of 288 normal control participants. Adult symptoms of ADHD were measured by both self-report and report of a significant other. Results indicated that the parents of children with ADHD had higher ratings of inattention/cognitive problems, hyperactivity/restlessness, impulsivity/emotional lability, and lower self-concept than parents of children without ADHD on both self-report and other-report ratings. Within the ADHD sample of children, other-report ratings of inattention/cognitive problems and impulsivity/emotional lability were higher for biological parents compared to nonbiological parents whereas self-ratings were not related to biological status. These findings support previous research documenting familial aggregation of ADHD and appear to strengthen the hypothesis that there is a genetic contribution to ADHD.     

Judgment of blame in teenagers with Asperger's syndrome

The judgment of blame was studied in a group of 28 teenagers, 14 with Asperger syndrome (AS) and 14 typically developed. Teenagers in each group were matched by age, cognitive development and academic level. They were presented with 12 short vignettes in which they had to judge an action according to the intent of the actor (deliberate and accidental), the consequences of the action (presence and absence) and the seriousness of the situation (low, medium and high). Results showed a significant difference in the patterns of judgment of both groups. The AS group judged the action according to the physical consequence of the action more than the intent of the actor; the opposite was observed with the control group. In addition, the AS teenagers were less capable than the control group of grading injury to a person when apportioning blame especially when they were not familiar with the social situations. This result suggests that the judgement of the seriousness of the outcome of the social interaction is linked with its level of familiarity. Furthermore, result are congruent with the assumption that two different cognitive structures, deontic reasoning and perspective taking, are involved in the judgment of blame.