Amount of General Factor Saturation in the Beck Anxiety Inventory Responses of Outpatients with Anxiety Disorders

To ascertain the amount of general factor saturation underlying the Beck Anxiety Inventory (BAI; Beck and Steer 1993) responses of anxious patients, the BAI was administered to 525 outpatients with DSM-IV-TR anxiety disorders. McDonald’s omega_hierarchical(ω _h) (Zinbarg et al. 2005) was calculated to estimate the amount of general factor saturation; ω _h is the amount of variance explained by a general (second-order) factor underlying a scale composed of multiple items divided by the total amount of variance explained by all of the scale’s items. An iterated principal-factor analysis was first performed and followed by a Schmid-Leiman transformation to determine the amount of variance explained by the second-order factor. ω _h was 0.70 [95% CI 0.66–0.72], and this value was discussed as supporting the current practice of summing the 21 symptom ratings of the BAI to estimate the overall severity of self-reported anxiety.

Estimation of a Latent Variable Regression Growth Curve Model for Individuals Cross-Classified by Clusters

The cross-classified multiple membership latent variable regression (CCMM-LVR) model is a recent extension to the three-level latent variable regression (HM3-LVR) model which can be utilized for longitudinal data that contains individuals who changed clusters over time (for instance, student mobility across schools). The HM3-LVR model can include the initial status on growth effect as varying across those clusters and allows testing of more flexible hypotheses about the influence of initial status on growth and of factors that might impact that relationship, but only in the presence of pure clustering of participants within higher-level units. This Monte Carlo study was conducted to evaluate model estimation under a variety of conditions and to measure the impact of ignoring cross-classified data when estimating the incorrectly specified HM3-LVR model in a scenario in which true values for parameters are known. Furthermore, results from a real-data analysis were used to inform the design of the simulation. Overall, it would be recommended for researchers to utilize the CCMM-LVR model over the HM3-LVR model when individuals are cross-classified, and to use a bare minimum of more than 100 clustering units in order to avoid overestimation of the level-3 variance component estimates.     

测验信度估计：从α系数到内部一致性信度

沿用经典的测验信度定义, 简介了信度与a 系数的关系以及a系数的局限。为了推荐替代a系数的信度估计方法, 深入讨论了与a 系数关系密切的同质性信度和内部一致性信度。在很一般的条件下, 证明了a 系数和同质性信度都不超过内部一致性信度, 后者不超过测验信度, 说明内部一致性信度比较接近测验信度。总结出一个测验信度分析流程, 说明什么情况下a 系数还有参考价值; 什么情况下a 系数不再适用, 应当使用内部一致性信度(文献上也常称为合成信度)。提供了计算同质性信度和内部一致性信度的计算程序, 一般的应用工作者可以直接套用。     

Signal detection theory with item effects

Applications of signal detection theory (SDT) often involve presentations of different items on each trial, such as slides in a medical imaging study or words in a memory study. If factors particular to the items themselves, apart from being a signal or noise, affect observers’ responses, then ‘item effects’ are present. One way to model these effects is to use a latent continuous variable as an item ‘factor’, such as item ‘difficulty’. Details of SDT models with item effects are clarified via derivations of their implied conditional means, variances, and covariances. Intra-item correlations are defined and suggested as measures of the magnitude of item effects. The SDT-item models are simple random coefficient models and can be fit with standard software. More general models, such as item models with mixing and/or with random observer effects, are also considered.     

Social Dominance Orientation and Right‐Wing Authoritarianism: Additive and Interactive Effects on Political Conservatism

It is commonly accepted that social dominance orientation (SDO) and right‐wing authoritarianism (RWA) are potent unique predictors of a variety of prejudice and prejudice‐related constructs. However, contrary to some predictions, there has been little evidence that these constructs interact to produce this outcome—they appear to be additive but not interactive in their prediction of prejudice. We extend the interaction hypothesis to consideration of another broadly relevant construct—political ideology. Drawing from 14 independent New Zealand–based samples, we show, through meta‐analysis and multilevel random coefficient modelling, that SDO and RWA additively and interactively predict levels of political conservatism operationalised in a variety of ways. Specifically, both constructs are associated with increasing political conservatism, and the lowest levels of conservatism (or highest levels of political liberalism) are found in those lowest in both SDO and RWA.     

Coactive processing of sensory signals for in-group but not out-group stimuli

ABSTRACT

There is ample evidence showing that decision times are shorter when detecting two targets for which the same response is required, compared to when only one of the targets is present—resulting in a redundancy gain. Though effects of perceptual manipulations on redundancy gains are established, effects of social associations are still unclear. Here, we examined for the first time whether associating arbitrary stimuli with in-group as opposed to out-group targets modulates redundancy gains. Participants made associations between a shape, a colour and either in- or out-group labels. They then had to discriminate whether in- or out-group stimuli appeared (single or redundant features). Responses to in-group but not to out-group stimuli violated predictions of models in which the associated features are processed independently, and were consistent with in-group stimuli being processed with super-capacity. Our results, replicated across two experiments, providing the first evidence that there is enhanced perceptual integration for information associated with an in-group.     

A family of association coefficients for metric scales

Four types of metric scales are distinguished: the absolute scale, the ratio scale, the difference scale and the interval scale. A general coefficient of association for two variables of the same metric scale type is developed. Some properties of this general coefficient are discussed. It is shown that the matrix containing these coefficients between any number of variables is Gramian. The general coefficient reduces to specific coefficients of association for each of the four metric scales. Two of these coefficients are well known, the product-moment correlation and Tucker's congruence coefficient. Applications of the new coefficients are discussed.     

A modification of Feldt's test of the equality of two dependent alpha coefficients

The available statistical tests of the equality of nonindependent alpha reliability coefficients require that the product of the number of test parts times the number of subjects be quite large—1000 or more. A modification of one of these tests is derived which avoids this limitation. Monte Carlo studies indicate that the modified test effectively controls the Type I error rate with as few as 2 or 3 test parts and 50 subjects. This means the modified test can be safely employed in comparisons between interrater reliabilities.     

Coefficients alpha and reliabilities of unrotated and rotated components

It has been shown by Kaiser that the sum of coefficients alpha of a set of principal components does not change when the components are transformed by an orthogonal rotation. In this paper, Kaiser's result is generalized. First, the invariance property is shown to hold for any set of orthogonal components. Next, a similar invariance property is derived for the reliability of any set of components. Both generalizations are established by considering simultaneously optimal weights for components with maximum alpha and with maximum reliability, respectively. A short-cut formula is offered to evaluate the coefficients alpha for orthogonally rotated principal components from rotation weights and eigenvalues of the correlation matrix. Finally, the greatest lower bound to reliability and a weighted version are discussed.Comments by Henk A.L. Kiers and by anonymous referees are gratefully acknowledged.     

Extension of Feldt's approach to testing homogeneity of coefficients of reliability

Limitations and extensions of Feldt's approach to testing the equality of Cronbach's alpha coefficients in independent and matched samples are discussed. In particular, this approach is used to test equality of intraclass correlation coefficients.This work was supported by the National Institute of Mental Health Specialized Research Center Grant # MH-30854.