对变化/分割模型的检验(I)

用两个实验对变化／分割模型进行了检验。实验１控制目标时距和该时距内的填充数字系列,操纵数字系列的分割段数;实验２控制目标时距内的填充数字系列的间距,操纵目标时距及其中填充数字系列的分割段数,要求被试用再现法和多数估计法分别复制目标时距,并进行立即估计和延迟估计。结果显示：与存储容量模型和加工时间模型相比较,变化／分割模型对时间估计的解释具有更高的预测效度     

Expanding the rasch model to a general model having more than one dimension

The well-known Rasch model is generalized to a multicomponent model, so that observations of component events are not needed to apply the model. It is shown that the generalized model has retained the property of the specific objectivity of the Rasch model. For a restricted variant of the model, maximum likelihood estimates of its parameters and a statistical test of the model are given. The results of an application to a mathematics test involving six components are described.     

新世纪20年国内结构方程模型方法研究与模型发展

新世纪前20年, 国内结构方程模型(SEM)方法研究主要涉及5个主题：模型发展、参数估计、模型评价、测量不变性及特殊数据处理, 特别是模型发展方面(即SEM的各种变式)有较多成果。对每个主题, 在简述背景知识的基础上, 系统总结了方法学研究发展及成果。最后也讨论了SEM的国外方法学研究进展和未来研究方向。     

Refining the two‐parameter testlet response model by introducing testlet discrimination parameters

For testlet response data, traditional item response theory (IRT) models are often not appropriate due to local dependence presented among items within a common testlet. Several testlet‐based IRT models have been developed to model examinees' responses. In this paper, a new two‐parameter normal ogive testlet response theory (2PNOTRT) model for dichotomous items is proposed by introducing testlet discrimination parameters. A Bayesian model parameter estimation approach via a data augmentation scheme is developed. Simulations are conducted to evaluate the performance of the proposed 2PNOTRT model. The results indicated that the estimation of item parameters is satisfactory overall from the viewpoint of convergence. Finally, the proposed 2PNOTRT model is applied to a set of real testlet data.     

A Note on Motor Learning Without Post-Response Knowledge of Results

The authors studied the adjustment of the 2 distinct known expressions of gait velocity, the velocity of the center of gravity (CG) and the velocity of the center of foot pressure (CP) at the end of the 1st step in 2 experimental situations: natural gait initiation (the control situation, CS) and heel-off gait initiation (the test situation, TS). Gait was initiated by 7 healthy participants, from an erect spontaneous posture in the CS and from a posture with heels raised in the TS, on a force platform at 3 self-selected speed conditions. Biomechanical data from the force platform were collected in both experimental situations, and the authors used a particular gait analysis based on the differential method of Y. Brenière (2003) in order to approach velocity modulation by means of step length and frequency. Results showed that CG and CP velocities were adjusted differently during heel-off gait initiation than during natural gait initiation. CP velocity, as compared with CG velocity, was overestimated in TS. Results also established the relevance of the expression of step velocity by means of step length and frequency: The central nervous system, taking into account the specific postural constraints of each experimental situation, uses a reference value and a regulating parameter to modulate step velocity. Moreover, the contributions of 1st step length and frequency to the expression of step velocity in TS and CS were different. Thus, a specific locomotor behavior corresponds to a given experimental situation that is characterized by its own initial biomechanical constraints.     

Facilitation of Psychomotor Learning by Classically Differentiated Supplementary Feedback Cues

2 experiments on the control of psychomotor performance by classically differentiated supplementary feedback cues are reported. The first, conducted with 30 Ss as a replication of an earlier study, demonstrated again that otherwise ineffective supplementary cues can be transformed into highly effective regulators of psychomotor performance by differential conditioning procedures. The second, conducted with 78 Ss, showed that the effects of classically differentiated supplementary cues on tracking skill increased as a negatively accelerated function of the number of differentiation trials. Results were interpreted as exemplifying the operation of secondary drive and reinforcement principles, although the nonspecific transfer of arousal and/or warm-up effects were acknowledged as worthy alternatives.     

Fungible Weights in Multiple Regression

Every set of alternate weights (i.e., nonleast squares weights) in a multiple regression analysis with three or more predictors is associated with an infinite class of weights. All members of a given class can be deemed fungiblebecause they yield identical SSE (sum of squared errors) and R ² values. Equations for generating fungible weights are reviewed and an example is given that illustrates how fungible weights can be profitably used to evaluate parameter sensitivity in multiple regression. The author wishes to thank Drs. Robyn Dawes, William Grove, Markus Keel, Leslie Yonce, Joe Rausch, the editor, and three anonymous reviewers for helpful comments on earlier versions of this article.     

儿童绘图作业内隐学习智力独立性研究

实验采用中性参数程序和绘图作业,让正常智力、轻度智力落后、中度智力落后3组8～12岁右利手儿童接受符合、不符合或与“起始-旋转法则”无关的绘图练习,考察练习对原初行为方式的影响。结果发现,违反“起始-旋转法则”的练习使智力落后组被试的绘图行为发生了明显改变,证明内隐学习具有智力独立性;“意识污染”对内隐学习结果的影响可能是复杂的而非单向的;中性参数实验程序能够更好地隐蔽规则学习的实验目的,但不能有效消除意识污染的影响。     

Mean Comparison: Manifest Variable Versus Latent Variable

Mean comparisons are of great importance in the application of statistics. Procedures for mean comparison with manifest variables have been well studied. However, few rigorous studies have been conducted on mean comparisons with latent variables, although the methodology has been widely used and documented. This paper studies the commonly used statistics in latent variable mean modeling and compares them with parallel manifest variable statistics. Our results indicate that, under certain conditions, the likelihood ratio and Wald statistics used for latent mean comparisons do not always have greater power than the Hotelling T² statistics used for manifest mean comparisons. The noncentrality parameter corresponding to the T² statistic can be much greater than those corresponding to the likelihood ratio and Wald statistics, which we find to be different from those provided in the literature. Under a fixed alternative hypothesis, our results also indicate that the likelihood ratio statistic can be stochastically much greater than the corresponding Wald statistic. The robustness property of each statistic is also explored when the model is misspecified or when data are nonnormally distributed. Recommendations and advice are provided for the use of each statistic. The research was supported by NSF grant DMS-0437167 and Grant DA01070 from the National Institute on Drug Abuse. We would like to thank three referees for suggestions that helped in improving the paper.