Model comparison of nonlinear structural equation models with fixed covariates

Recently, it has been recognized that the commonly used linear structural equation model is inadequate to deal with some complicated substantive theory. A new nonlinear structural equation model with fixed covariates is proposed in this article. A procedure, which utilizes the powerful path sampling for computing the Bayes factor, is developed for model comparison. In the implementation, the required random observations are simulated via a hybrid algorithm that combines the Gibbs sampler and the Metropolis-Hastings algorithm. It is shown that the proposed procedure is efficient and flexible; and it produces Bayesian estimates of the parameters, latent variables, and their highest posterior density intervals as by-products. Empirical performances of the proposed procedure such as sensitivity to prior inputs are illustrated by a simulation study and a real example.This research is fully supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region, China (Project No. CUHK 4346/01H). The authors are thankful to the Editor, the Associate Editor, and anonymous reviewers for valuable comments which improve the paper significantly, and grateful to ICPSR and the relevant funding agency for allowing use of the data in the example. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged.     

A person-fit index for polytomous rasch models,latent class models,and their mixture generalizations

A normally distributed person-fit index is proposed for detecting aberrant response patterns in latent class models and mixture distribution IRT models for dichotomous and polytomous data.This article extends previous work on the null distribution of person-fit indices for the dichotomous Rasch model to a number of models for categorical data. A comparison of two different approaches to handle the skewness of the person-fit index distribution is included.Major parts of this paper were written while the first author worked at the Institute for Science Education, Kiel, Germany. Any opinions expressed in this paper are those of the authors and not necessarily of Educational Testing Service. The results presented in this paper were improved by valuable comments from J. Rost, K. Yamamoto, N.D. Verhelst, E. Bedrick and two anonymous reviewers.     

Equivalence relations in individuals with language limitations and mental retardation

The study of equivalence relations exhibited by individuals with mental retardation and language limitations holds the promise of providing information of both theoretical and practical significance. We reviewed the equivalence literature with this population, defined in terms of subjects having moderate, severe, or profound mental retardation. The literature includes 55 such individuals, most of whom showed positive outcomes on equivalence tests. The results to date suggest that naming skills are not necessary for positive equivalence test outcomes. Thus far, however, relatively few subjects with minimal language have been studied. Moreover, we suggest that the scientific contributions of studies in this area would be enhanced with better documentation of language skills and other subject characteristics. With recent advances in laboratory procedures for establishing the baseline performances necessary for equivalence tests, this research area is poised for rapid growth.     

Unemployment, Underemployment, and Mental Health: Conceptualizing Employment Status as a Continuum

The economy is one of the most important social environments that affect well-being, and community psychologists have long studied the social costs of one key economic stressor—job loss. But economically inadequate employment has received much less research attention than unemployment in regard to mental health effects. This paper contrasts these two literatures and considers factors that might account for their differential growth including actual rates of unemployment and underemployment. Recent panel studies offer no support for another possible basis for this differential growth—the assumption that inadequate employment is more like adequate employment than unemployment. Implications of a paradigm shift from a dichotomous perspective (employment vs. unemployment) to a continuum perspective with variations of both unemployment and employment are discussed for research and prevention. Another implication is the need to expand standard labor force statistics to reflect better the degree of underemployment.     

Hostile attributional tendencies in maltreated children

The hostile attributional tendencies of maltreated children in elementary school across key relationship figures (i.e., parents, teachers, and peers), the relation between children's hostile attributional tendencies and the frequency and severity of maltreatment, and the role of children's hostile attributions of their parents in mediating the relation between maltreatment and children's hostile attributions of unfamiliar peers were examined. The sample consisted of 44 maltreated and 56 nonmaltreated children (females = 51) of mixed ethnicity. Subjects were administered a 20-item measure of attributional processes. The results indicated that relative to nonmaltreated children, physically abused boys were more likely to attribute hostile intentions to a variety of relationship figures, including their parents, an unfamiliar teacher, their best friend, and unfamiliar peers. A positive relation was also found between the frequency of physical abuse and hostile attributional tendencies among males. Finally, support was found for the role of children's hostile attributions of their mothers in mediating the relation between physical abuse and children's hostile attributions of unfamiliar peers. The results support a link between physical abuse and hostile attributional tendencies in children in early elementary school.     

The Role of Creativity in Marriage and Family Therapy Practice: A National Online Study

The purpose of this study, using an online methodology, was to investigate therapists' perceptions of the role of creativity in couples' and family therapy. Along with completing a quantitative measure assessing creativity in their work, participants responded to four open-ended questions which addressed the meaning of creativity, characteristics of a creative family therapist, some creative interventions they have used with couples and families, and barriers to their own creativity as a family therapist. A total of 142 marriage and family therapists in 36 states in the United States participated. The findings shed light on the unique importance of creativity in couples and family treatment.     

A note on the equivalence of the graded response model and the sequential model

This paper concerns items that consist of several item steps to be responded to sequentially. The item scoreX is defined as the number of correct responses until the first failure. Samejima's graded response model states that each steph=1,...,m is characterized by a parameterb _h , and, for a subject with ability, Pr(Xh; )=F(–b _h ). Tutz's general sequential model associates with each step a parameterdh, and it states that Pr(Xh;)= _r ^=1h G(–d _r ). Tutz's (1991, 1997) conjectures that the models are equivalent if and only ifF(x)=G(x) is an extreme value distribution. This paper presents a proof for this conjecture.     

时间记忆层次网络模型的实验检验

实验采用分类性实验材料,使被试在对词单项目加工时形成较清晰的群集,进而形成时间组块,目的在于对时间记忆层次网络进行直接检验。其中时序判断用反时间时和正确率两种反应指标,时距估计用再现和口头估计两种方法。结果发现,时间信息记忆既存在层次网络的特征,又存在线性结构的特征。     

心算加工年老化及其机制研究

以１７２名２０－７９岁成人为被式对心算加工的年老化过程及其机制进行了研究。任务为连续减法心算,依难度分为５种：１０００－１,１０００－３,１０００－１３及１０００－１７。结果表明,年龄与心算难度存在明显的交互作用,且随着年龄增加,不同难度心算效率均以幂函数形式降低。