Constrained maximum likelihood estimation of two-level covariance structure model via EM type algorithms

In this paper, the constrained maximum likelihood estimation of a two-level covariance structure model with unbalanced designs is considered. The two-level model is reformulated as a single-level model by treating the group level latent random vectors as hypothetical missing-data. Then, the popular EM algorithm is extended to obtain the constrained maximum likelihood estimates. For general nonlinear constraints, the multiplier method is used at theM-step to find the constrained minimum of the conditional expectation. An accelerated EM gradient procedure is derived to handle linear constraints. The empirical performance of the proposed EM type algorithms is illustrated by some artifical and real examples.This research was supported by a Hong Kong UCG Earmarked Grant, CUHK 4026/97H. We are greatly indebted to D.E. Morisky and J.A. Stein for the use of their AIDS data in our example. We also thank the Editor, two anonymous reviewers, W.Y. Poon and H.T. Zhu for constructive suggestions and comments in improving the paper. The assistance of Michael K.H. Leung and Esther L.S. Tam is gratefully acknowledged.     

Every Finitely Reducible Logic has the Finite Model Property with Respect to the Class of ♦-Formulae

In this paper a unified framework for dealing with a broad family of propositional multimodal logics is developed. The key tools for presentation of the logics are the notions of closure relation operation and monotonous relation operation. The two classes of logics: FiRe-logics (finitely reducible logics) and LaFiRe-logics (FiRe-logics with local agreement of accessibility relations) are introduced within the proposed framework. Further classes of logics can be handled indirectly by means of suitable translations. It is shown that the logics from these classes have the finite model property with respect to the class of -formulae, i.e. each -formula has a -model iff it has a finite -model. Roughly speaking, a -formula is logically equivalent to a formula in negative normal form without occurrences of modal operators with necessity force. In the proof we introduce a substantial modification of Claudio Cerrato's filtration technique that has been originally designed for graded modal logics. The main core of the proof consists in building adequate restrictions of models while preserving the semantics of the operators used to build terms indexing the modal operators.     

Effects of practice and task constraints on stiffness and friction functions in biological movements

A dynamical model of the movements of the platform of a ski-simulator was derived from experimental data, using the graphical and statistical methods developed by Beek and Beek (Beek, P. J., & Beek, W. J. (1988). Human Movement Science, 7, 301–342). The data were collected in an experiment in which both amplitude and practice were manipulated. The data were filtered and further reduced to normalised cycles that were averaged within and across subjects. Graphical methods were applied to these averaged normalised cycles to determine the stiffness and friction terms to be included in the model. The relative contribution of each term was assessed by means of multiple regression. The model, which included cubic and quintic Duffing terms and one or two dissipative Van der Pol terms, accounted on average for 99.2% of the variance. The exact parameter setting of the model differed considerably across subjects. For one subject, a qualitatively different model, including Rayleigh instead of Van der Pol terms, provided a better account of the data. Systematic changes of the coefficients in the model, related to amplitude and the duration of practice, were evident.     

The Treatment Planning of Experienced Counselors: A Qualitative Examination

Using consensual qualitative research, the authors examined the treatment planning process of experienced counselors (N = 9). The data analysis resulted in 4 domains: assessment steps, clinical impressions, treatment factors, and treatment strategies. These domains describe the process used by experienced counselors in making clinical decisions and offer insight into the nature of clinical expertise and the need for further research on treatment planning.     

Using finite mixture of GLMs to explore variability in children's flexibility in a task-switching paradigm

The present study illustrates the usefulness of finite mixture of generalized linear models (GLMs) to examine variability in cognitive strategies during childhood. More precisely, it addresses this variability in set-shifting situations where task-goal updating is endogenously driven. In a task-switching paradigm 5–6-year-olds had to switch between color- and shape-matching rules as a function of a predetermined, predictable task sequence. A finite mixture of GLMs was fitted to explore individual differences in performance. The statistical model revealed five response profiles, defined by accuracy and response times. These response profiles likely correspond to different cognitive strategies with varying efficiency and differential relations to working memory capacity (assessed by backward digit span). These results illustrate the heuristic value of statistical modeling to reveal the behavioral and cognitive variability in the temporal dynamics of children's cognitive functioning.     

A calibration explanation of serial position effects in evaluative judgments

Judges often evaluate stimulus series on dimensions for which no physical scale exists; for example, when judging academic ability in oral examinations. We propose that judges deal with this problem by calibrating an internal judgment scale that maps stimulus input onto available judgment categories. This calibration process implies serial position effects: Judges should initially avoid extreme categories, because using extreme categories reduces judgmental degrees of freedom, thereby increasing the possibility of internal consistency violations. In four experiments, we show that judgments become indeed more extreme later in a series of judgments. Judges evaluated the same good (poor) performances more positive (negative) at the end of a sequence compared to the beginning. Judges’ expertise did not prevent the effect, but allowing end-of-sequence judgments reduced serial position effects. We discuss the implications and possible remedies of these calibration effects on judgment extremity.     

Longitudinal associations of cognitive ability,personality traits and school grades with antisocial behaviour

This study investigated the role of adolescents' cognitive ability, personality traits and school success in predicting later criminal behaviour. Cognitive ability, the five‐factor model personality traits and the school grades of a large sample of Estonian schoolboys (N = 1919) were measured between 2001 and 2005. In 2009, judicial databases were searched to identify participants who had been convicted of misdemeanours or criminal offences. Consistent with previous findings, having a judicial record was associated with lower cognitive ability, grade point average, agreeableness, and conscientiousness and higher neuroticism. In multivariate path models, however, the contributions of cognitive ability and conscientiousness were accounted for by school grades and the effect of neuroticism was also accounted for by other variables, leaving grade point average and agreeableness the only independent predictors of judicial record status. Copyright © 2011 John Wiley & Sons, Ltd.     

进化心理学对心理素质结构研究的整合与重构——以学生心理素质结构研究为例

传统的心理素质结构研究模式不经济,研究结果出现纵向断裂横向分裂的趋势.从进化心理学的视角来看,心理素质结构的最终功能均指向个体的适应性,其形成是与周围环境不断排斥和融合的过程.建构的心理素质结构融合模型能在一定程度上解决传统研究模式的弊端,并建议今后的研究应以分析人为主导转而分析人及其所处的文化环境并重,进而引导人的心理素质结构的不断发展.     

基于文化的心理复原力研究

随着对个体心理复原力研究不断深入,文化作为影响个体心理复原力的重要因素日益受到关注,研究者在厘清文化与复原力之间的关系后,尝试以积极心理学的视角,将中国传统文化中"天人合一"、"以人为本"、"自强不息"、"厚德载物"等文化精神引入到个体心理复原力发展的过程中,为个体心理复原力的研究贡献价值。     

高校多媒体教学环境下的教-学-学习绩效关系的建模与分析

本文是在先前建立的多媒体教学环境下教师授课、学生学习和学习绩效的3个因素结构模型基础上,采用路径建模技术,建立了多媒体教学环境下教一学一学习绩效关系模型。基于对该路径模型的分析,获得如下结论：（1）多媒体教学中影响因素的主导作用是沿着学习者认知加工过程中的信息流而展开的;（2）对于学生在课堂中的信息加工,影响最大的因素是教师授课时对学生的能力培养,影响为其次的因素是教师的授课技术;（3）课件的良好界面信息设计对学生的知识掌握起重要作用;（4）诸如授课速度过快、信息量过大等多媒体教学中的易现问题会增加学生的外在认知负荷而降低学习效果;（5）在多媒体教学中,教师与学生都要注意学生学习风格来更好地进行教学或学习。