Distinguishing the Ratio Bias from Unsystematic Error: Situation and Individual‐difference Effects

People often perceive the occurrence of events to be less likely when the likelihood of the event is expressed in ratios consisting of smaller numbers versus larger numbers, an effect known as the ratio bias. This work presents a theoretical framework for the conditions that need to be met for the ratio bias to occur. In doing so, we contrast effects on the ratio bias to those on unsystematic error, which have often been confounded in previous research. We find that the ratio bias is weaker (1) when both sets of numbers are relatively large than when both sets of numbers are relatively small; (2) for scenarios involving lottery tickets than for scenarios involving drawing balls from a bin; and (3) when a physical display depicting the numbers is provided to participants. Each of these factors reduced the ratio bias without reducing unsystematic error. Additionally, we show that unsystematic error is lower among people who (1) reason on the basis of proportions rather than on the basis of the numerator and denominator individually; (2) score higher on the rational scale of the Rational–Experiential Inventory; and (3) are of higher numeracy. We use these results to distinguish causes of error generally from those on the ratio bias specifically and discuss the implications for our understanding of when the ratio bias occurs. Copyright © 2018 John Wiley & Sons, Ltd.     

A Note on the Power of Multiattribute One‐switch Utility Functions

One‐switch utility functions model situations in which the preference between two alternatives switches only once as the outcome of one attribute of both alternatives changes from low to high. Recent research cites evidence that the sum of exponential functions (sumex) is the most convincing type for modelling one‐switch utility functions. Sumex functions allow to model exactly one preferential switch and they are convenient for estimating one‐switch utility functions. However, it is unclear so far if sumex functions are suitable to model preferential switches that are perceivable by a decision maker. This paper first analyses how different the utility of two alternatives before and after a preferential can be modelled with sumex functions given that the preferential switch is caused by a particular attribute outcome improvement. It thereafter investigates how accurately decision makers perceive such utility differences. Copyright © 2015 John Wiley & Sons, Ltd.     

Measurement issues in health-related quality of life: Challenges for health psychology

Abstract

Quality of life assessment is a central element of clinical trials and related forms of evaluative research. Early efforts to establish appropriate methods of measuring quality of life drew on psychometric principles and emphasised the need for validated measures. However, it is increasingly clear that, whilst still a central requirement of quality of life measures, validity needs to be emphasised alongside a number of other essential properties that have become clearer as the field has developed. Moreover formal psychometric methodology has to be adapted to take account of the specific needs of evaluative research. Research is beginning to develop more appropriate methods of outcome assessment in this area. Further lines of research are suggested to examine psychometric with other approaches to measurement of health-related quality of life.     

Generating Recommendations for Simulator Design Through Pilot Assessment of Prototype Utility

Incorporated in a simulator design project, this study assessed the utility of a simulator prototype for air combat training to optimize continued development. After several scenarios, the 13 male participants completed a survey. Seven fidelity levels: visual feedback, head-up/head-down, instrumentation, flight controls, graphics, visual resolution, and field-of-view were rated for three dimensions: realism, limitation of performance, and importance of realism. The results informed decisions about which fidelity levels, head-up/head-down and field-of-view, that should be prioritized during the next design cycle, and generated recommendations for continued simulator design and directives for further evaluations.     

Visual Power in Action: Digital Images and the Shaping of Medical Practices

The increasing presence of images in medicine is mostly understood as a visualization of medicine. In this view, physicians and researchers are strongly guided by the visual power of images. Ethnographic fieldwork and interviews with physicians and scientists working in radiology departments and magnetic resonance imaging units however, show that visual power is not always effective. Depending on a situation, physicians and scientists are guided more strongly either by the persuasiveness of an image's visual qualities or its scientific and sociomaterial qualities. Actors trust in images and perceive them as attractive and objective in certain situations, whereas in others they classify images as manipulated representations that are untrustworthy. It is either the visual power or the status of images as scientific and sociomaterial facts that shapes physicians' and researchers' actions. Depending on whether an image is used, for example, to make a diagnosis, to validate a research finding, to communicate with a patient, to prevent litigation, or to improve one's position in the professional field, it is either the visual power or the scientific and sociomaterial characteristics of an image that are more effective in shaping medical practices. Fieldwork and interviews with physicians and scientists show in which situations visual power is relevant (or not) for medical practices.     

Probabilistic choice (models) as a result of balancing multiple goals

We conceptualize probabilistic choice as the result of the simultaneous pursuit of multiple goals in a vector optimization representation, which is reduced to a scalar optimization that implies goal balancing. The majority of prior theoretical and empirical work on such probabilistic choice is based on random utility models, the most basic of which assume that each choice option has a valuation that has a deterministic (systematic) component plus a random component determined by some specified distribution. An alternate approach to probabilistic choice has considered maximization of one quantity (e.g., utility), subject to constraints on one or more other quantities (e.g., cost). The multiple goal perspective integrates the results regarding the well-studied multinomial logit model of probabilistic choice that has been derived from each of the above approaches; extends the results to other models in the generalized extreme value (GEV) class; and relates them to recent axiomatic work on the utility of gambling.     

最优化与满意型决策风格孰优孰劣?

最优化决策者追求决策的最优解,满意型决策者寻求决策的满意解.已有研究以理性模型和有限理性模型为基础,提出了两类决策风格的概念并且从两类决策者的决策特征和心理指标这两个角度详细对比了两类决策风格的差异.就纯粹的经济学效益、主观的心理学意义和现实的决策选择这三方面而言,“两类决策风格孰优孰劣”是一个因人而异,因决策目标而异的问题.未来研究可以在清晰界定两类决策风格概念的基础上进一步完善测量工具,从而深入探讨两类决策风格的领域特异性、与正性情绪的关系及其心理悖论的根源.     

决策的三参照点理论:从原理到应用

三参照点理论(Tri-Reference Point Theory,Wang,2008a; Wang& Johnson,2012)以底线、现状和目标为参照点,将决策结果空间划分为失败、损失、获益和成功4个功能区域.根据3个参照点的心理权重的排序:底线＞目标＞现状,该模型继而推导出跨越不同区域的以现状为分界的双S-型的价值函数,以及据此产生的对于跨越不同参照点的预期结果的偏好转换、和损失-获益及失败-成功的两种不对称性.总之,风险决策的基本任务在于,在使得达到目标的可能性最大化的同时使底线不保的可能性最小化.三参照点理论将统计学和金融学中的均值与方差(均差)分析与行为决策研究中的参照点效应有机地结合在一起;在面对不同的风险选项时,通过分析各个预期结果的均差分布与3个参照点之间的关系作出适应性的决策.本文介绍了三参照点理论的基本推论、运行原则、实证检验、以及它与期望效用理论和前景理论相比较的异同之处.同时我们也探讨了三参照点理论对实践中管理决策的指导意义和多重启示.     

时间定价对亲社会行为的影响

时间定价就是将金钱价格赋予时间之上,用金钱来衡量时间的价值。已有研究表明,时间定价激活时间经济价值最大化的心理定势,使个体更看重时间的经济回报,花更少的时间帮助他人。但是,时间定价对亲社会行为的影响可能并不仅仅局限于时间利他。本研究通过三个实验,除了考察时间定价对时间利他的影响外,还进一步探讨时间定价对金钱利他的影响。结果显示,时间定价不仅影响个体的时间利他行为,也削弱了金钱利他行为。这表明,时间定价所激活的经济效用心理定势不仅仅局限于时间这一种资源的效用。     

Subjective expected utility without preferences

This paper proposes a theory of subjective expected utility based on primitives only involving the fact that an act can be judged either “attractive” or “unattractive”. We give conditions implying that there are a utility function on the set of consequences and a probability distribution on the set of states such that attractive acts have a subjective expected utility above some threshold. The numerical representation that is obtained has strong uniqueness properties.