A general Bayesian multilevel multidimensional IRT model for locally dependent data

Many item response theory (IRT) models take a multidimensional perspective to deal with sources that induce local item dependence (LID), with these models often making an orthogonal assumption about the dimensional structure of the data. One reason for this assumption is because of the indeterminacy issue in estimating the correlations among the dimensions in structures often specified to deal with sources of LID (e.g., bifactor and two-tier structures), and the assumption usually goes untested. Unfortunately, the mere fact that assessing these correlations is a challenge for some estimation methods does not mean that data seen in practice support such orthogonal structure. In this paper, a Bayesian multilevel multidimensional IRT model for locally dependent data is presented. This model can test whether item response data violate the orthogonal assumption that many IRT models make about the dimensional structure of the data when addressing sources of LID, and this test is carried out at the dimensional level while accounting for sampling clusters. Simulations show that the model presented is effective at carrying out this task. The utility of the model is also illustrated on an empirical data set.     

A review of research on smoking among United States Veterans with posttraumatic stress disorder (2006–2016)

Posttraumatic stress disorder (PTSD) is one of the most common psychiatric disorders diagnosed in U.S. veterans. PTSD is associated with high smoking prevalences and difficulty quitting in the general U.S. population. The current study reviewed research on smoking and PTSD in U.S. veteran samples to summarize past research and identify areas in need of additional inquiry. MEDLINE and PsycINFO searches identified papers on smoking in samples of U.S. veterans with PTSD published from January 2006 through December 2016. Thirty-four articles met all of the inclusion criteria: (a) part of the sample consisted of U.S. veterans with PTSD or PTSD symptoms, and (b) the study examined some aspect of smoking behavior. U.S. veterans with PTSD were more likely to report smoking, heavy smoking, nicotine dependence, and late-onset smoking compared to veterans without PTSD. Smoking behaviors (e.g., current smoking, heavy smoking, smoking expectancies) differed by PTSD symptoms and by combat exposure. Smoking cessation feasibility studies examined the integration of smoking treatment into PTSD clinics and found favorable outcomes. Future research on veterans with PTSD would benefit from extending topics beyond rates of smoking to better understand the treatment needs of veterans. Research on smoking-related behaviors can help identify areas to target for interventions.     

消费决策中的零：零价格效应和零比较效应

数字“0”由于自身所具有的特性(最小的自然数和不可作为被除数),当其与商品的价格维度和属性维度相结合时会对消费者的决策产生影响。已有研究表明商品的零价格和零属性会对消费决策产生影响,即零价格效应和零比较效应。情绪和社会规范是零价格效应产生的心理机制,参照依赖则是零比较效应产生的心理机制。商品价格、商品类型和消费者的心理因素是零价格效应的边界条件;而选项的数量是零比较效应的边界条件。未来的研究可以从不同商品类型、不同社会规范、“价格-损失”与“价格-质量”、注意等角度对零价格效应进行深入研究;也可以从结构匹配模型和齐当别模型的角度进一步探索零比较效应的“比较”机制;可以探讨价格是否能被视为商品的“坏属性”,进而讨论零价格效应和零比较效应二者之间的关系。     

情绪对职业价值观的影响——意义建构的中介作用

为了考察情绪对于职业价值观的影响,本研究采用情绪量表、意义建构量表、职业价值观量表以及社交媒体依赖程度量表等,对938名员工数据进行检验,结果表明:(1)情绪对于职业价值观具有显著的正向影响;(2)意义建构在情绪与职业价值观之间起完全中介作用;(3)社交媒体依赖程度负向调节了情感与意义建构之间的关系。情绪通过意义建构的中介作用对职业价值观产生影响,并且社交依赖在路径的前半段起调节作用。探究情绪与职业价值观关系,对于科学树立合理的职业价值观具有重要意义。     

Factors Associated with Functional Dependence in Alzheimer's Disease

The purpose of this study was to determine whether common geriatric conditions, family function, and nutritional problems have independent associations with functional dependence beyond the effect of cognitive impairment in patients with Alzheimer's disease. It was found that some common geriatric conditions affecting patients with Alzheimer's disease appear to have multiple and differential relationships with specific instrumental activities of daily living (IADLs) dependency. These results have implications for medical care. Preventing one condition may not be sufficient to prevent further IADL dependences because the conditions are independently related to individual outcome variables. Thus, multiple conditions may need to be managed concurrently if further functional dependence is to be expected.     

RELIGION AND SCIENCE IN AN ADVANCED SCIENTIFIC CULTURE

Abstract. These are reflections on the Arkansas creationist trial by a witness for the American Civil Liberties Union. The following points are stressed: First, religion took the lead in defending science at the trial. Second, the appearance of creation science is a function not only of Protestant fudamentalism but also of the establishment of science in our wider culture. It represents a "deviant science" in such a culture. Third, our century has manifested many such bizarre unions of ideological religion and modern science. This shows that science is dependent upon its humanistic, moral, and religious matrix for its social and historical health. Fourth, part of the cause of the rise of creation science has been the power, status, and self–assurance of science that it represents "the only form of truth." Fifth, religion in turn tends both to increase and to become fanatical in advanced and precarious cultures; religion, therefore, needs rational and moral criticism if it would help in the creation of social health.     

Multivariate normal integrals and contingency tables with ordered categories

Ak-dimensional multivariate normal distribution is made discrete by partitioning thek-dimensional Euclidean space with rectangular grids. The collection of probability integrals over the partitioned cubes is ak-dimensional contingency table with ordered categories. It is shown that loglinear model with main effects plus two-way interactions provides an accurate approximation for thek-dimensional table. The complete multivariate normal integral table is computed via the iterative proportional fitting algorithm from bivariate normal integral tables. This approach imposes no restriction on the correlation matrix. Comparisons with other numerical integration algorithms are reported. The approximation suggests association models for discretized multivariate normal distributions and contingency tables with ordered categories.The contingency-table approach occurred to me while I was collaborating with Paul Holland of the Educational Testing Service in 1985 on bivariate dependence functions. Holland maintains a belief that the continuous can learn from the discrete. This work is a reassertion of his claim.This research was sponsored by the National Science Council, Republic of China.     

Tail-measurability in monotone latent variable models

We consider latent variable models for an infinite sequence (or universe) of manifest (observable) variables that may be discrete, continuous or some combination of these. The main theorem is a general characterization by empirical conditions of when it is possible to construct latent variable models that satisfy unidimensionality, monotonicity, conditional independence, andtail-measurability. Tail-measurability means that the latent variable can be estimated consistently from the sequence of manifest variables even though an arbitrary finite subsequence has been removed. The characterizing,necessary and sufficient, conditions that the manifest variables must satisfy for these models are conditional association and vanishing conditional dependence (as one conditions upon successively more other manifest variables). Our main theorem considerably generalizes and sharpens earlier results of Ellis and van den Wollenberg (1993), Holland and Rosenbaum (1986), and Junker (1993). It is also related to the work of Stout (1990).The main theorem is preceded by many results for latent variable modelsin general—not necessarily unidimensional and monotone. They pertain to the uniqueness of latent variables and are connected with the conditional independence theorem of Suppes and Zanotti (1981). We discuss new definitions of the concepts of true-score and subpopulation, which generalize these notions from the stochastic subject, random sampling, and domain sampling formulations of latent variable models (e.g., Holland, 1990; Lord & Novick, 1968). These definitions do not require the a priori specification of a latent variable model.The authors made equivalent contributions to the results of this article. Ellis' research was supported by the Dutch Interuniversitary Graduate School of Psychometrics and Sociometrics. Junker's research was supported by ONR Grant N00014-87-K-0277, NIMH Grant MH15758, and a Carnegie Mellon University Faculty Development Grant. In addition Junker would like to acknowledge the hospitality of the Nijmegen Institute for Cognition and Information during his visit to the University of Nijmegen in August 5–10, 1993.     

Trace autoshaping: Acquisition, maintenance, and path dependence at long trace intervals

The pigeon's tendency to acquire and maintain signal-directed key pecking under a trace conditioning procedure was parametrically examined. In Experiment 1, the percentage of CS trials with a key peck response was a decreasing function of the trace interval for separate groups of pigeons. The majority of subjects acquired signal-directed key pecking with trace intervals as long as 36 sec. In Experiment 2, differential maintenance of key pecking occurred across trace intervals in a within-subject procedure. Maintenance of key pecking at 36- and 60-sec trace intervals was path dependent in that responding depended on the subject's performance under the preceding trace interval.