元回归中效应量的最小个数需求：基于统计功效和估计精度

元回归模型被广泛应用于调节变量的识别。从元分析技术的原理谈起, 介绍了元回归模型, 然后采用蒙特卡洛模拟, 基于统计功效和估计精度探究效应量个数对元回归模型参数估计的影响, 从而确立效应量的最小个数需求。主要研究结果为：(1) Wald-type z检验方法在元回归中易犯I类错误; (2)为达到参数估计要求, 元回归至少需要20个效应量; (3)纳入合适的调节变量能降低对效应量的个数需求。基于研究结果, 提出以下建议：(1)研究者应慎重使用Wald-type z检验方法和CMA软件; (2)研究者至少需要20个效应量, 且应当根据实际情况进一步增加效应量个数; (3)研究者应当积极探索合适的调节变量; (4)未来审稿人可参考最小效应量个数需求对元回归研究进行质量评估。     

Hemispheric laterality measured in Rembrandt's portraits using pupil diameter and aesthetic verbal judgements

Eckhard Hess claimed that pupils dilate to pleasant images and constrict to unpleasant images. However, his work was confounded since his image's luminances and contrasts across conditions were inconsistent. We overcome this limitation and suggest a new, promising methodology for research in this area. We presented rightward or leftward facing male and female portraits by Rembrandt to observers in either their original or mirror-reversed position. Since emotional content may be expressed differently on each side of the face, we used Rembrandt's portraits since most of his males had their right-cheek exposed and females had their left-cheek exposed. This raises questions regarding the emotional and cognitive significance of such biased positioning. Simultaneously, we measured observers pupil size while asking observers to report how (dis)pleasing they found each image. We found that in viewing male portraits pupil diameter was a function of arousal. That is, larger pupil diameter occurred for images rated both low and high in pleasantness. We discuss these findings in regard to the perceived dominance of males and how emotional expressions may be driven by hemispheric laterality.     

Teacher perceptions of student behavior as a function of class size

In an attempt to describe class size effects on student behavior that might be predictable from one setting to the next, the author proposes a social psychology framework. He hypothesizes that social loafing, deindividuation, and social facilitation can explain patterns of student participation, off-task behavior, and in-class performance, respectively, as a function of the size of the class. Data from interviews with eight middle-school teachers suggest that these concepts are marginally applicable to the behaviors in question. At the same time, other class size effects on student behavior are described which may be inherent in class size and thus be reasonably predictable. Josh Englehart is a recent PhD receipient from Cleveland State University. He is currently a public school Physical Education teacher in Painesville, Ohio. His research to date has included class size effects on various outcome variables, teacher perceptions of student intelligence, and student motivation.     

Network Size, Social Support and Happiness in Later Life: A Comparative Study of Beijing and Hong Kong

This study investigates how happiness of elderly Chinese is related to their social support networks, based on survey data collected in 2000 from Beijing and Hong Kong. These two Chinese cities share a common cultural heritage but differ in social-economic structure. It was found that in both cities, income is more significant than gender and education in determining happiness, but it is less important than personal network size and particularly perceived social support. More importantly, findings from the two cites consistently lend support to the thesis that older persons with a larger network are happier and that social support plays a mediating role. Controlling for social-demographic factors does not change this pattern of relationships. There are, however, differences between the two cities. Beijing’s elderly were found to be happier and have larger social networks than Hong Kong’s elderly. Also, our explanatory models consistently account for less variance in the happiness of older persons in Beijing. These findings are probably due to the differences between socialist Beijing and capitalist Hong Kong in degrees of modernization and urbanization and in social organization of work and community life.     

At what sample size do latent variable correlations stabilize?

We conducted a Monte-Carlo simulation within a latent variable framework by varying the following characteristics: population correlation (ρ = 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, and 1.00) and composite score reliability (coefficient omega: ω = 0.40, 0.50, 0.60, 0.70, 0.80, and 0.90). The sample sizes required to estimate stable measurement-error-free correlations were found to approach N = 490 for typical research scenarios (population correlation ρ = 0.20; composite score reliability ω = 0.70) and as high as N = 1000+ for data associated with lower, but still sometimes observed, reliabilities (ω = 0.40–0.50). We encourage researchers to take into consideration reliability, when evaluating the sample sizes required to produce stable measurement-error-free correlations.     

Correlating the internal length in strain gradient plasticity theory with the microstructure of material

The internal length is the governing parameter in strain gradient theories which among other things have been used successfully to interpret size effects at the microscale. Physically, the internal length is supposed to be related with the microstructure of the material and evolves during the deformation. Based on Taylor hardening law, we propose a power-law relationship to describe the evolution of the variable internal length with strain. Then, the classical Fleck–Hutchinson strain gradient theory is extended with a strain-dependent internal length, and the generalized Fleck–Hutchinson theory is confirmed here, by comparing our model predictions to recent experimental data on tension and torsion of thin wires with varying diameter and grain size. Our work suggests that the internal length is a configuration-dependent parameter, closely related to dislocation characteristics and grain size, as well as sample geometry when this affects either the underlying microstructure or the ductility of the material.     

The coupled effect of grain size and solute on work hardening of Cu–Ni alloys

A modified grain size-dependent model developed to capture the combined effects of solute and grain size on the work hardening behaviour of fine-grained Cu–Ni alloys is provided. This work builds on a recent model that attributes the grain size-dependent work hardening of fine-grained Cu to backstresses. In the case of Cu–Ni alloys, unlike commercially pure Cu, a grain size-dependent separation between the Kocks–Mecking curves develops, this being explained here based on an extra contribution from geometrically necessary dislocations in the solid solution alloy. This is corroborated by strain-rate sensitivity experiments.     

The pros and cons of funnel plots as an aid to risk communication and patient decision making

Funnel plots, which simultaneously display a sample statistic and the corresponding sample size for multiple cases, have a range of applications. In medicine, they are used to display treatment outcome rates and caseload volume by institution, which can inform strategic decisions about health care delivery. We investigated lay people's understanding of such plots and explored their suitability as an aid to individual treatment decisions. In two studies, 172 participants answered objective questions about funnel plots representing the surgical outcomes (survival or mortality rates) of institutions varying in caseload, and indicated their preferred institutions. Accuracy for extracting objective information was high, unless question phrasing was inconsistent with the plot's survival/mortality framing, or participants had low numeracy levels. Participants integrated caseload‐volume and outcome‐rate data when forming preferences, but were influenced by reference lines on the plot to make inappropriate discriminations between institutions with similar outcome rates. With careful choice of accompanying language, funnel plots can be readily understood and are therefore a useful tool for communicating risk. However, they are less effective as a decision aid for individual patient's treatment decisions, and we recommend refinements to the standard presentation of the plots if they are to be used for that purpose.     

一种基于进化算法的概化理论最佳样本量估计新方法：兼与三种传统方法比较

概化理论在心理与教育测量领域应用较广。如何使测量程序在预算限制的情况下达到较优的可靠性是研究者需要考虑的重要问题, 这个问题可以转换为最佳样本量估计的问题。提出了一种基于进化算法的估计概化理论下最佳样本量的新方法——约束进化算法, 并采用模拟研究的方法比较了微分优化法、拉格朗日法、柯西不等式法等三种传统方法与约束进化算法的优劣。结果表明：在两侧面交叉设计、两侧面嵌套设计和三侧面交叉设计中都证明了约束进化算法更具优越性, 建议研究者在今后的研究中优先使用。     

Synchronising self-displacement with a cross-traffic gap: How does the size of traffic vehicles impact continuous speed regulations?

In this article, we investigated what visual information is used by drivers at a road crossing when they want to synchronize their displacement with that of an incoming traffic train. We made the hypothesis that synchronizing self-displacement with that of a traffic gap shares the same perceptual-motor basis as interception tasks. While a large body of literature demonstrates that bearing angle is used to control interception, another range of studies points to optical size and expansion as playing a critical role in collision avoidance. In order to test the hypothesis of the exclusive use of bearing angle in road crossing task, we manipulated the optical size and expansion of oncoming traffic elements independently of bearing angle variations. We designed a driving simulator study in which participants were to adjust their approach speed in order to cross a road junction within a moving traffic gap. We manipulated the initial offset of participants with the traffic gap, the geometry of the road junction and the way optical size of oncoming traffic elements evolves over the course of a trial. Our results showed an effect of optical size and optical expansion manipulations eventhough, we also found similar displacement profiles as in interception studies. This demonstrates that bearing angle could not explain alone the control of such a complex perceptual-motor task. We discuss these results with regard to similar results in other fields of literature.