Checking the Assumptions of Rasch's Model for Speed Tests

Two new tests for a model for the response times on pure speed tests by Rasch (1960) are proposed. The model is based on the assumption that the test response times are approximately gamma distributed, with known index parameters and unknown rate parameters. The rate parameters are decomposed in a subject ability parameter and a test difficulty parameter. By treating the ability as a gamma distributed random variable, maximum marginal likelihood (MML) estimators for the test difficulty parameters and the parameters of the ability distribution are easily derived. Also the model tests proposed here pertain to the framework of MML. Two tests or modification indices are proposed. The first one is focused on the assumption of local stochastic independence, the second one on the assumption of the test characteristic functions. The tests are based on Lagrange multiplier statistics, and can therefore be computed using the parameter estimates under the null model. Therefore, model violations for all items and pairs of items can be assessed as a by-product of one single estimation run. Power studies and applications to real data are included as numerical examples.     

Functional recovery of skilled forelimb use in rats obliged to use the impaired limb after grafting of the frontal cortex lesion with homotopic fetal cortex

The long-term effect of transplanting embryonic frontal cortex into a unilateral frontal cortex lesion has been studied in adult rats. Before surgery, activity in an open field, muscular strength of both forelimbs, and performance in a paw-reaching-for-food task were scored in 26 rats. In 21 animals a unilateral cortex lesion was then made in the forelimb motor area of the hemisphere contralateral to the preferred paw in the paw-reaching-for-food task, while the other 5 animals were sham-operated. On retesting, the lesion animals changed the preferred paw. A solid homotopic transplant of embryonic tissue (embryonic day 17) was then placed in the lesion cavity in 11 of the lesion rats. Three months later neither lesion alone nor lesion plus transplantation affected open field behavior and muscular strength, but the lesion permanently affected performance in the paw-reaching-for-food task, as shown by a change of preferred paw and a functional deficit in the paw contralateral to the lesion. Transplantation ameliorated the deficits caused by the lesion, but this was only evident when animals were forced to reach with the paw contralateral to the lesion plus transplant. The behavioral results were independent of the size of the lesion and graft. Connections between graft and host tissue were studied by means of the fluorescent tracer 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI). A dense array of labeled fibers was found in the host cortex adjacent to the transplant. The results suggest that functional recovery depends on grafting but is only evident when the animal is obliged to use the affected limb.     

The import of infancy for individual, family, and societal development: commentary on the special section: does infancy matter?

Across their life spans humans actualize a rich potential for cognitive and behavioral plasticity, a set of developmental changes that require regulation of organism-context relations on the part of both the individual and society. An individual’s action on the context must be started in infancy and maintained in subsequent periods of life for adaptive functioning to occur across ontogeny. The process of the individual acting as an agent of his or her own development is continuous, although the particular ways in which such control is manifested will change in developmentally appropriate ways. As demonstrated by the papers in this special issue, the significance of infancy for the rest of the life-span rests on an integration of this continuity and discontinuity within the person-context developmental system.     

Elaboration et validation de tests de jugement situationnel comme outil de sélection professionnelle : guide méthodologique

Current views in personnel selection recognize the necessity for situational judgements tests (SJT) which are closed to the real work context of companies. The SJTs have also become a popular selection tool across Europe. SJTs are attractive because they show good validity, positive applicants reactions and can be cost effective to test large group of applicants at once. The aim of this paper is to describe a structured methodology for the elaboration of such test. Each stage is illustrated by examples and psychometrics validation issues are discussed.     

基于作答时间数据的改变点分析在检测加速作答中的探索——已知和未知项目参数

相对于传统的离散作答数据, 作答时间作为连续数据, 可以提供更多信息。改变点分析(change point analysis)技术在心理和教育领域是一个比较新的技术。本文一方面对改变点分析在心理测量领域的应用进行了一个综合的总结和分析; 另一方面, 将基于作答数据的两种改变点分析统计量推广到作答时间数据, 将改变点分析技术应用到测验异常作答模式：加速作答speededness的检测上。采用两种检验方法：似然比检验和Wald检验, 分别在已知和未知项目参数的条件下, 实现异常作答模式的检测。结果表明, 所采用的方法对于加速作答行为的检测具有很高的检验力, 同时能够很好的控制I类错误率。实证数据分析进一步表明本文中所使用的方法具有应用价值。     

新世纪20年国内假设检验及其关联问题的方法学研究

新世纪20年来国内假设检验方法学研究内容可分为如下几类: 零假设显著性检验的不足、p值的使用问题、心理学研究的可重复性问题、效应量、检验力、等效性检验、其他与假设检验关联的研究。零假设显著性检验已经发展成一套组合流程: 为了保证检验力和节省成本, 实验研究需要做先验检验力分析预估样本容量, 但问卷超过160人在传统统计中就没有必要这样做。当拒绝零假设时, 应当结合效应量做出结论。当不拒绝零假设时, 需要报告后验检验力; 如果效应量中或大而检验力不够高, 则可增加被试再行分析, 但这一过程应主动披露, 报告最后的实际p值并对可能犯的第一类错误率做出评估。     

If I imagine it,then it happened: The Implicit Truth Value of imaginary representations

Imagination sometimes leads people to behave, feel, and think as though imagined events were real even when they know they were not. In this paper, we suggest that some understanding of these phenomena can be achieved by differentiating between Implicit Truth Value (ITV), a spontaneous truth evaluation, and Explicit Truth Value (ETV), a self-reported truth judgment. In three experiments, we measure ITV using the autobiographical Implicit Association Test (Sartori, Agosta, Zogmaister, Ferrara, & Castiello, 2008), which has been used to assess which of two autobiographical events is true. Our findings demonstrate that imagining an event, like experiencing an event, increases its ITV, even when people explicitly acknowledge the imagined event as false (Experiments 1a and 1b). Furthermore, we show that imagined representations generated from a first-person perspective have higher ITV than imagined representations generated from a third-person perspective (Experiment 2). Our findings suggest that implicit and explicit measures of truth differ in their sensitivity to properties underlying truth judgment. We discuss the contribution of characterizing events according to both ITV and ETV to the understanding of various psychological phenomena, such as lying and self-deception.