Meta-analysis of correlation coefficients: A Monte Carlo comparison of fixed- and random-effects methods.

The efficacy of the Hedges and colleagues, Rosenthal-Rubin, and Hunter-Schmidt methods for combining correlation coefficients was tested for cases in which population effect sizes were both fixed and variable. After a brief tutorial on these meta-analytic methods, the author presents 2 Monte Carlo simulations that compare these methods for cases in which the number of studies in the meta-analysis and the average sample size of studies were varied. In the fixed case the methods produced comparable estimates of the average effect size; however, the Hunter-Schmidt method failed to control the Type I error rate for the associated significance tests. In the variable case, for both the Hedges and colleagues and Hunter-Schmidt methods, Type I error rates were not controlled for meta-analyses including 15 or fewer studies and the probability of detecting small effects was less than .3. Some practical recommendations are made about the use of meta-analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The grateful disposition: A conceptual and empirical topography.

In four studies, the authors examined the correlates of the disposition toward gratitude. Study 1 revealed that self-ratings and observer ratings of the grateful disposition are associated with positive affect and well-being, prosocial behaviors and traits, and religiousness/spirituality. Study 2 replicated these findings in a large nonstudent sample. Study 3 yielded similar results to Studies 1 and 2 and provided evidence that gratitude is negatively associated with envy and materialistic attitudes. Study 4 yielded evidence that these associations persist after controlling for Extraversion/positive affectivity, Neuroticism/negative affectivity, and Agreeableness. The development of the Gratitude Questionnaire, a unidimensional measure with good psychometric properties, is also described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Syndromes of retrograde amnesia: A conceptual and empirical synthesis.

This article attempts a synthesis of the range of disorders that have been subsumed under the rubric of retrograde amnesia. At a functional level, it is possible to make distinctions between various forms of retrograde amnesia, including a distinction between episodic amnesia for personally experienced events and semantic retrograde amnesia for components of knowledge, such as those relating to people and events. At an anatomical level, discrete lesions to limbic-diencephalic structures usually result in a limited degree of retrograde amnesia. Marked episodic or marked semantic retrograde amnesia is usually associated with significant involvement of cortical and neocortical structures. Retrograde amnesia is a functionally heterogeneous rather than a unitary phenomenon. Discontinuities and dissociations found in published studies point to the potential fractionation of retrograde amnesia into component disorders, each with its own neural profile. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A conceptual and empirical review of the depressive realism hypothesis.

Reviews the depressive realism hypothesis that suggests that depressed persons may be more accurate in their perceptions of various situations than are nondepressed persons. The theoretical implications of depressive realism are examined and problematic aspects of assessing the depressive realism hypothesis are clarified. Distortion and realism are distinguished, and the results of a review of 3 substantive areas of research, judgment of contingency studies, performance feedback studies, and interpersonal judgment and feedback studies, are discussed. Positive evidence for the existence of depressive realism was found although the strength of that finding diminished as the ecological validity of studies increased. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing for Suspected Impairments and Dissociations in Single-Case Studies in Neuropsychology: Evaluation of Alternatives Using Monte Carlo Simulations and Revised Tests for Dissociations.

In neuropsychological single-case studies, a patient is compared with a small control sample. Methods of testing for a deficit on Task X, or a significant difference between Tasks X and Y, either treat the control sample statistics as parameters (using z and zD) or use modified t tests. Monte Carlo simulations demonstrated that if z is used to test for a deficit, the Type I error rate is high for small control samples, whereas control of the error rate is essentially perfect for a modified t test. Simulations on tests for differences revealed that error rates were very high for zD. A new method of testing for a difference (the revised standardized difference test) achieved good control of the error rate, even with very small sample sizes. A computer program that implements this new test (and applies criteria to test for classical and strong dissociations) is made available. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A conceptual and empirical analysis of the cognitive ability–voluntary turnover relationship.

Despite much research into cognitive ability as a selection tool and a separate large literature on the causes of voluntary turnover, little theoretical or empirical work connects the two. We propose that voluntary turnover is also a potentially key outcome of cognitive ability. Incorporating ideas from the person–environment fit literature and those regarding push and pull influences on turnover, we posit a theoretical connection between cognitive ability and voluntary turnover that addresses both why and how voluntary turnover is related to cognitive ability. Integrating data from 3 different sources, our empirical analyses support the theoretical perspective that the relationship between cognitive ability and voluntary turnover depends on the cognitive demands of the job. When the cognitive demands of a job are high, our findings support the hypothesized curvilinear relationship between cognitive ability and voluntary turnover, such that employees of higher and lower cognitive ability are more likely than medium cognitive ability employees to leave voluntarily. With regard to jobs with low cognitive demands, our data are more consistent with a negative linear relationship between cognitive ability and voluntary turnover, such that higher cognitive ability employees are less likely to leave voluntarily. We also examine the role of job satisfaction, finding that job satisfaction is more strongly linked to voluntary turnover in jobs with high cognitive demands. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of halo error on appraisal effectiveness: A conceptual and empirical reconsideration.

Examined gaps and weaknesses in the rater error–accuracy literature and drew conclusions about the usefulness of this line of inquiry, given the current nature of the measures and the state of theories. It is argued that in prior work in this area, particularly with respect to the question of halo error, the implication of alternative measures of halo or accuracy has not been considered in sufficient detail. It is also suggested that, conceptually, variance and correlational forms of halo and accuracy may yield identical, corresponding, or widely divergent results. Empirical evidence is used to illustrate how results that appear counterintuitive, as have been reported in other studies, can often be explained as a necessary outcome, given the construction of the halo and accuracy measures. 170 students rated 5 vignettes describing instructor classroom behavior. A direct test of the notion that halo can be controlled statistically is offered, and it is found that even when halo has been shown to have the expected effect on accuracy, statistically controlling for this influence does not improve rating validity. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

GaN MOCVD生长速率及表面形貌随生长参数的变化

根据现有氮化镓(GaN)金属有机物化学气相淀积(Metalorganic Chemical Vapor Deposotion)生长动力学理论,结合具体的MOCVD反应腔体的构造,用计算流体力学和动力学蒙特卡罗方法对GaN MOcvD生长过程中的生长速率和表面形貌演变进行了计算机模拟.结果表明,在950～1350 K的温度范围内反应气体充分热分解,是适合GaN外延生长的温度区间;温度低于950 K,反应气体未能充分地分解,导致较低的生长速率;而温度高于1350 K则Ga组分的脱附现象开始变得严重,从而抑制GaN的生长速率.另一方面,较高的v/Ⅲ也会抑制GaN的生长速率.生长过程中表面形貌随时间的演变结果显示,GsN薄膜在高温下(1073～1473 K)为2D层状生长,在1373 K的温度下生长的GaN薄膜表面最为平整.     

The empirical and conceptual value of the spiritual transcendence and religious involvement scales for personality research.

Despite their wide usage, the constructs of spirituality and religiosity have no universally accepted definitions, and very little research has examined how these numinous constructs relate both to one another and to established personality dimensions. Two studies are presented that examined the factor structure of a motivationally based measure of spirituality, the Spiritual Transcendence Scale (STS) and a behaviorally based measure of religiosity, the Religious Involvement Scale (RIS). Three causal models examining their relationships to one another and to psychological measures of growth and maturity, as well as their incremental validity in predicting a wide array of psychosocial outcomes over the influence of the Five-Factor Model domains were examined. Employing self and observer ratings and American and Filipino samples, the results demonstrated that these robust, cross-culturally generalizable scales provided insights into people not contained by traditional personality variables. The conceptual implications of these results were discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of Criteria for Classical Dissociations in Single-Case Studies by Monte Carlo Simulation.

The conventional criteria for a classical dissociation in single-case studies require that a patient be impaired on one task and within normal limits on another. J. R. Crawford and P. H. Garthwaite (2005) proposed an additional criterion, namely, that the patient's (standardized) difference on the two tasks should differ from the distribution of differences in controls. Monte Carlo simulation was used to evaluate these criteria. When Type I errors were defined as falsely concluding that a control case exhibited a dissociation, error rates were high for the conventional criteria but low for Crawford and Garthwaite's criteria. When Type I error rates were defined as falsely concluding that a patient with equivalent deficits on the two tasks exhibited a dissociation, error rates were very high for the conventional criteria but acceptable for the latter criteria. These latter criteria were robust in the face of nonnormal control data. The power to detect classical dissociations was studied. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of closed testing procedures for pairwise testing of means.

A Monte Carlo simulation was conducted to compare 9 pairwise multiple comparison procedures. Procedures were evaluated on the basis of any-pair power and all-pairs power. No procedure was found to be uniformly most powerful. A modification due to A. J. Hayter (1986) of Fisher's least significant difference was found to provide the best combination of ease of use and moderately high any-pair power in most cases. Pilot or exploratory studies can expect good power results with this relatively simple procedure. The greatest all-pairs power was usually provided by 1 of 2 partition-based versions of E. Peritz's (1970) procedure. Confirmatory studies will require such complex methods but may also need larger sample sizes than have been customary in psychological research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical and empirical examination of the chi-square test for homogeneity of correlations in meta-analysis.

This article statistically and empirically examines the chi-square test of homogeneity of effect sizes when that test is applied to correlation coefficients and to their Fisher's r-to-z transformation equivalents. Shows that the test on untransformed rs has excessively high Type I error rates as a result of distribution characteristics of r but that the test performs nominally for Fisher's r-to-z transformation values. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beyond alpha: An empirical examination of the effects of different sources of measurement error on reliability estimates for measures of individual-differences constructs.

On the basis of an empirical study of measures of constructs from the cognitive domain, the personality domain, and the domain of affective traits, the authors of this study examine the implications of transient measurement error for the measurement of frequently studied individual-differences variables. The authors clarify relevant reliability concepts as they relate to transient error and present a procedure for estimating the coefficient of equivalence and stability (L. J. Cronbach, 1947), the only classical reliability coefficient that assesses a 3 major sources of measurement error (random response, transient, and specific factor errors). The authors conclude that transient error exists in all 3 trait domains and is especially large in the domain of affective traits. Their findings indicate that the nearly universal use of the coefficient of equivalence (Cronbach's alpha; L. J. Cronbach, 1951), which fails to assess transient error, leads to overestimates of reliability and undercorrections for biases due to measurement error. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Safety climate and injuries: An examination of theoretical and empirical relationships.

Our purpose in this study was to meta-analytically address several theoretical and empirical issues regarding the relationships between safety climate and injuries. First, we distinguished between extant safety climate→injury and injury→safety climate relationships for both organizational and psychological safety climates. Second, we examined several potential moderators of these relationships. Meta-analyses revealed that injuries were more predictive of organizational safety climate than safety climate was predictive of injuries. Additionally, the injury→safety climate relationship was stronger for organizational climate than for psychological climate. Moderator analyses revealed that the degree of content contamination in safety climate measures inflated effects, whereas measurement deficiency attenuated effects. Additionally, moderator analyses showed that as the time period over which injuries were assessed lengthened, the safety climate→injury relationship was attenuated. Supplemental meta-analyses of specific safety climate dimensions also revealed that perceived management commitment to safety is the most robust predictor of occupational injuries. Contrary to expectations, the operationalization of injuries did not meaningfully moderate safety climate–injury relationships. Implications and recommendations for future research and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of the Extreme Groups Approach: A Critical Reexamination and New Recommendations.

Analysis of continuous variables sometimes proceeds by selecting individuals on the basis of extreme scores of a sample distribution and submitting only those extreme scores to further analysis. This sampling method is known as the extreme groups approach (EGA). EGA is often used to achieve greater statistical power in subsequent hypothesis tests. However, there are several largely unrecognized costs associated with EGA that must be considered. The authors illustrate the effects EGA can have on power, standardized effect size, reliability, model specification, and the interpretability of results. Finally, the authors discuss alternative procedures, as well as possible legitimate uses of EGA. The authors urge researchers, editors, reviewers, and consumers to carefully assess the extent to which EGA is an appropriate tool in their own research and in that of others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trait configurations in self-managed teams: A conceptual examination of the use of seeding for maximizing and minimizing trait variance in teams.

In this article, the authors argue that there is no one best way to make placement decisions on self-managed teams. Drawing from theories of supplementary and complementary fit, they develop a conceptual model that suggests that (a) maximization principles should be applied to extroversion variance (i.e., complementary fit), (b) minimization principles should be applied to conscientiousness variance (i.e., supplementary fit), and (c) extroversion variance and conscientiousness variance interact to influence team performance. They also argue that previous research has underestimated the effect of extroversion and conscientiousness variance on performance because of suboptimal design. The authors, therefore, present an alternative method for making team placement decisions (i.e., seeding) that can be used to maximize or minimize variance in teams. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of Event Scale: A cross-validation study and some empirical evidence supporting a conceptual model of stress response syndromes.

Conducted a cross-validational study on the Impact of Event Scale (IES), a self-report instrument assessing the essential characteristics associated with stress disorders. 35 bereaved outpatients completed the IES before entering time-limited dynamic psychotherapy and at 4 and 12 mo following termination. A further 28 Ss, not participating in therapy, completed the measure at similar intervals. Results confirm the scale's relevance, internal consistency, and sensitivity. In addition, data are interpreted as consistent with a clinically derived theoretical model of the pattern of response to serious life events. As predicted by the theory, the syndromatic group showed greater intensity of intrusive and avoidance states; the relevant salience of reported experience was similar across groups; and the syndromatic group before intervention was characterized by an absence of a movement toward completion of processing the meaning of the event. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of implicit measures for organizational research: An empirical example.

An increasing amount of attention is being paid by social and cognitive psychologists to implicit processing, which has ubiquitous effects on attitudes and behaviours. Unfortunately, organizational scholars have tended to focus almost exclusively on explicit processing, which limits understanding of how employees function at work if implicit processing does indeed play a role. In this article, the authors argue that implicit processing is likely prevalent in organizational settings and discuss ways that it can be measured. The authors then present the results of an experiment that suggests that organizational justice—an important work-based variable—has implicit effects on motivation. Moreover, the magnitude of explicit and implicit effects was moderated by need for cognition, a stable individual difference variable. These results support the need to examine implicit processing and its effects in organizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

新改进Monte Carlo法模拟钢板退火过程的晶粒长大

通过对传统MonteCarlo(MC)法的改进，提出了模拟钢板退火过程晶粒长大的新改进MC法，并与传统MC法和Radhakrishnan改进MC法进行比较。新改进的MC法主要特点是节点取向转向其他取向，只在该节点的邻近节点中选择，并且取体系能量降幅最大的取向。模拟结果表明，新改进MC法所模拟的组织最佳，晶粒长大指数n为0．47，接近理论值0．5，模拟速度较传统MC法和Radhakrishnan改进MC法更快。     

Evaluation of Karhunen–Loève, Spectral, and Sampling Representations for Stochastic Processes

The Karhunen–Loève, spectral, and sampling representations, referred to as the KL, SP, and SA representations, are defined and some features/limitations of KL-, SP-, and SA-based approximations commonly used in applications are stated. Three test applications are used to evaluate these approximate representations. The test applications include (1) models for non-Gaussian processes; (2) Monte Carlo algorithms for generating samples of Gaussian and non-Gaussian processes; and (3) approximate solutions for random vibration problems with deterministic and uncertain system parameters. Conditions are established for the convergence of the solutions of some random vibration problems corresponding to KL, SP, and SA approximate representations of the input to these problems. It is also shown that the KL and SP representations coincide for weakly stationary processes.