Sample size determination for a matched-pairs study with incomplete data using exact approach

This research was motivated by a clinical trial design for a cognitive study. The pilot study was a matched-pairs design where some data are missing, specifically the missing data coming at the end of the study. Existing approaches to determine sample size are all based on asymptotic approaches (e.g., the generalized estimating equation (GEE) approach). When the sample size in a clinical trial is small to medium, these asymptotic approaches may not be appropriate for use due to the unsatisfactory Type I and II error rates. For this reason, we consider the exact unconditional approach to compute the sample size for a matched-pairs study with incomplete data. Recommendations are made for each possible missingness pattern by comparing the exact sample sizes based on three commonly used test statistics, with the existing sample size calculation based on the GEE approach. An example from a real surgeon-reviewers study is used to illustrate the application of the exact sample size calculation in study designs.     

Does the Broaden-and-Build Theory Explain Reduction in Social Disruption After a Brief Relaxation Intervention for Women With Breast Cancer Undergoing Treatment?

Women with breast cancer experience social disruption during and after treatment. Brief cognitive-behavioral (CBT) and relaxation (RT) interventions may improve social disruption by increasing positive affect. Using the Broaden-and-Build Theory as a framework, this study examined whether short-term CBT- and RT-related increases in positive affect mediate long-term reductions in social disruption in women with breast cancer undergoing treatment (N = 183). This secondary analysis used latent change score and growth models to test 6- and 12-month intervention effects on positive affect and social disruption, respectively; a parallel-process model assessed mediation. RT demonstrated larger reductions in social disruption across 12 months compared to CBT and a health education control. Six-month latent change in positive affect was significant but not driven by condition. There was a significant direct effect linking the latent slopes of positive affect and social disruption but meditation was not observed. These preliminary findings hint at the value of promoting positive affect and inform the development of brief behavioral interventions that aim to augment social functioning among women surviving breast cancer.     

工作时间与工作绩效的非线性关系：一项元分析

基于42篇文献的64项独立研究, 总样本量为22843人的数据, 对工作时间与工作绩效的非线性关系进行了元分析。结果发现：(1)工作时间与任务绩效、关系绩效之间存在显著的倒U型关系; (2)国家类型的调节作用显著：相对于西方欧美国家, 工作时间与任务绩效、关系绩效的倒U型关系在中国更为显著; (3)产业类型的调节作用显著：相对于劳动、资本密集型产业, 工作时间与任务绩效的倒U型关系在知识密集型产业中更为显著; (4)年龄的调节作用显著：相对于高年龄水平, 工作时间与任务绩效的倒U型关系在低年龄水平群体中更为显著; (5)性别的调节作用显著：相对于低男性比例, 工作时间与关系绩效的倒U型关系在高男性比例群体中更为显著。结果不仅基于元分析厘清了工作时间与工作绩效的倒U型关系效应, 而且为劳动法中工时规定(例如周均工作时间不超过44小时)的合理性提供了科学依据, 警示组织注意工作时间对工作绩效的“过犹不及”效应。     

情感启发式对风险选择的影响

本研究旨在考察情感启发式对风险选择的影响。研究1采用线上和线下结合的方式对687名大学生进行问卷施测,修订并检验中文版情感启发式问卷的信效度,以该问卷测试的风险−收益相关系数作为衡量情感启发式倾向的指标。研究2采用极端被试法,在103名大学生完成问卷后,将风险−收益相关系数绝对值前20%和后20%的被试分为高、低情感启发式组,完成风险选择任务。结果发现：（1）中文版情感启发式问卷具有较好的信度与效度,可以作为情感启发式倾向的测试问卷。（2）风险选择任务激活负性情绪时,相比于低情感启发式倾向,高情感启发式倾向的被试更容易受负性情绪的影响,其风险判断的主观值更高。研究揭示了情感启发式对风险选择的影响,为情感启发式作为个体进行风险判断的重要依据提供了实证支持。     

青少年未来取向三种测试途径的比较

考察未来取向测试新方法（作品分析法）有效性及对比已有测量方法(自陈问卷法、行为测试法)的优缺点。结果发现,问卷法测得青少年未来取向水平随年龄增长逐渐降低,行为测试法和作品分析法测得青少年未来取向水平随年龄增长逐渐提高;问卷法测得未来取向与学校投入相关密切,行为测试法测得未来取向与学业成绩相关密切,作品分析法测得未来取向与学校投入、学业成绩均相关。作品分析法是一种有效测量青少年未来取向的新途径。     

How Affect Shapes Risky Choice: Distorted Probability Weighting Versus Probability Neglect

People's choices between prospects with relatively affect‐rich outcomes (e.g., medical side effects) can diverge markedly from their choices between prospects with relatively affect‐poor outcomes (e.g., monetary losses). We investigate the cognitive mechanisms underlying this “affect gap” in risky choice. One possibility is that affect‐rich prospects give rise to more distortion in probability weighting. Another is that they lead to the neglect of probabilities. To pit these two possibilities against each other, we fitted cumulative prospect theory (CPT) to the choices of individual participants, separately for choices between options with affect‐rich outcomes (adverse medical side effects) and options with affect‐poor outcomes (monetary losses); additionally, we tested a simple model of probability neglect, the minimax rule. The results indicated a qualitative difference in cognitive mechanisms between the affect‐rich and affect‐poor problems. Specifically, in affect‐poor problems, the large majority of participants were best described by CPT; in affect‐rich problems, the proportion of participants best described by the minimax rule was substantially higher. The affect gap persisted even when affect‐rich outcomes were supplemented by numerical information, thus providing no support for the thesis that choices in affect‐rich and affect‐poor problems diverge because the information provided in the former is nonnumerical. Our findings suggest that the traditional expectation‐based framework for modeling risky decision making may not readily generalize to affect‐rich choices. Copyright © 2015 John Wiley & Sons, Ltd.     

Effects of immediacy of feedback on estimations and performance

We investigated the role of anticipation of feedback in performance and estimation about own performance. We submitted 155 participants to a test of verbal aptitude, and we requested them to give estimations of their own performance and the performance of other participants. There were two treatments: immediate feedback and delayed feedback. Participants in the immediate‐feedback group were informed that they would receive feedback on their performance immediately after finishing the test, whereas participants in the delayed‐feedback group were informed that they would receive feedback a week after taking the test. The immediate‐feedback group performed better than the delayed‐feedback group. Furthermore, the former underestimated their own performance. On the other hand, participants on the delayed‐feedback group made unbiased estimations. We present a mathematical model based on construal‐level theory, decision affect theory, temporal discounting, and Moore and Healy's model of overestimation. The model suggests that the source of differences in performance and in estimations of own performance is a construal of the feedback situation that modifies the expected utility of the task.     

The Effect of Cognitive Complexity and Nature of the Outcome on Causal Attribution

Because even subtle forms of racial discrimination can damage well-being, identifying individual differences that shape this stress process is important. Dispositional forgiveness has been shown to influence how people perceive and react to interpersonal transgressions, yet its role in the context of racial discrimination has not received much research attention. In the current study, participants completed an initial measure of dispositional forgiveness and then considered a scenario that could be deemed racially discriminatory. Next, participants' perceptions of the scenario, negative affect, and cognitive performance were assessed. Dispositional forgiveness predicted all three outcomes such that more forgiving individuals were less likely to view the event as racially discriminatory and showed lower negative affect and greater cognitive performance after reading the scenario. Moreover, race moderated these relationships such that forgiveness played a more beneficial role for ethnic minorities than for whites.     

On Coffee Talk and Break-Room Chatter: Perceptions of Women Who Gossip in the Workplace

ABSTRACT

The present study examined perceptions of female gossipers in the workplace. Male and female participants (N = 129) were asked to think of a woman who either frequently or rarely contributed negative information about other people during conversation. Participants then completed ratings on the target using the six dimensions of the FIRO-B. As predicted, high gossipers were perceived as having a greater need to exert control of others, but less need for others to control them, than low gossipers. Higher gossipers were also perceived as less emotionally warm than low gossipers. The implications of these findings for gossip research are presented.