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301.
On the Notion of Substitution   总被引:1,自引:0,他引:1  
  相似文献   
302.
In testing hypotheses, researchers frequently have used multiple regression analysis to control for nuisance variables (i.e., potential confounding variables that are correlated with hypothesized causal variables). In this paper, we highlight limitations of this control strategy, and we discuss fundamental issues that should be considered in deciding whether to use it. Ultimately, we suggest the use of multiple regression analysis sometimes may not improve causal understanding and may actually limit the generalizability of results. Instead of the common practice of controlling for nuisance variables, we suggest that looking at shared variance frequently is a more appropriate test of a theoretical hypothesis.  相似文献   
303.
小学儿童CVS策略的发展及其对教育的启示   总被引:1,自引:0,他引:1  
CVS策略是国外不少研究者正深入研究的一种学习策略,关于它的研究得出了许多有价值的结论。本文首先分析了CVS的概念、研究方法和研究意义,然后对当前的研究结论进行了梳理,从五大方面详细分析了小学儿童CVS策略的发展特点,最后又从四个发面提出了这些研究对当前教育的启示。  相似文献   
304.
Political science traditionally conceptualizes efficacy only in relation to politics and government. In this article, we look beyond political efficacy and examine the effect of general self‐efficacy on young adults' voting behavior. General self‐efficacy, an individual's estimation of capacity to operate successfully across a variety of domains, is often important to the behavioral decisions of individuals entering a new domain of activity. With data from the Children of the National Longitudinal Study of Youth, we examine the effect of general self‐efficacy on voting behavior among young, first‐time voters. We find that general self‐efficacy has a positive effect on voter turnout, and this effect is strongest for young people from low socioeconomic‐status families.  相似文献   
305.
The paper discusses the psychotherapy of an adolescent who, during a psychotic breakdown, developed a mystical delusion on a religious theme. Splitting processes and the narcissistic defences that accompany them are illustrated. After showing how the patient had recourse to splitting and how the split-off parts of the ego took refuge inside an internal object, the ego's efforts to make contact once more with these split-off aspects and to reintegrate them are highlighted. With the help of certain concepts developed by, for example, Rosenfeld and Meltzer - specifically those relating to the organization of internal groupings or 'gangs' and their destructiveness and the compartmentalization of internal objects - the author shows how certain particularities of the patient's internal world can be understood in terms of these splitting processes. In addition the clinical material presented raises several technical questions, in particular those relating to dissociative processes and delusion or delusional theories as they become manifest in the treatment.  相似文献   
306.
For adolescents, the transition from comprehensive school to post-comprehensive education is one of the most important in this life phase. Future education-related personal goals, concerns, and related internal motivation are assumed to play key roles in a successful transition. The “Towards Working Life” group method was developed, among other objectives, to enhance internal motivation towards education-related goals, and to increase the number of personal goals and concerns related to future education. A total of 1034 ninth graders from comprehensive school were randomized into 25 intervention groups and control groups. A week-long group intervention, which took place at school, showed that the intervention increased the number of future education-related personal goals and that this effect was also related to an increase in similar concerns. Moreover, the intervention increased adolescents' internal motivation towards education-related goals.  相似文献   
307.
Abstract

Four variables were identified that predicted outcome for the minimal and moderate intensity weight control programs presented in sequence. Predictive models for pounds lost and percentage overweight lost were computed for both programs and follow-up and accounted for 33% to 62% of the variance. The predictor variable that contributed to the two programs and follow-up was success in losing weight previously. Greater rate of weight loss in the first five weeks contributed to the model for the minimal intensity program and for follow-up and total number of calories expended in nonroutine physical activity added to the model for the minimal intensity program. Marital dissatisfaction of subjects was a predictor for the moderate intensity program and follow-up. The findings have utility for a stepped program for weight and provide confirmation of variables noted as predictors in prior research. This study may help in the quest to identify consistent predictors of weight loss success.  相似文献   
308.
When modeling the relationship between two nominal categorical variables, it is often desirable to include covariates to understand how individuals differ in their response behavior. Typically, however, not all the relevant covariates are available, with the result that the measured variables cannot fully account for the associations between the nominal variables. Under the assumption that the observed and unobserved variables follow a homogeneous conditional Gaussian distribution, this paper proposesRC(M) regression models to decompose the residual associations between the polytomous variables. Based on Goodman's (1979, 1985)RC(M) association model, a distinctive feature ofRC(M) regression models is that they facilitate the joint estimation of effects due to manifest and omitted (continuous) variables without requiring numerical integration. TheRC(M) regression models are illustrated using data from the High School and Beyond study (Tatsuoka & Lohnes, 1988). This article was accepted for publication, when Willem J. Heiser was the Editor ofPsychometrika. This research was supported by grants from the National Science Foundation (#SBR96-17510 and #SBR94-09531) and the Bureau of Educational Research at the University of Illinois. We thank Jee-Seon Kim for comments and computational assistance.  相似文献   
309.
    
Motor imagery is a mental process not accompanied by movement and widely studied in healthy subjects, related to hand movements in terms of timing. This study compared static and dynamic motor imagery analyzing temporal and spatial features in different locomotor conditions in three different groups of subjects: high-skilled athletes with visual impairments, a group of sighted unprofessional athletes and a control group of sighted subjects. We found that dynamic motor imagery resulted in timely closer to real performance than static motor imagery. The discrepancies between dynamic motor imagery and real condition, in fact, resulted limited to uncommon locomotion, such as lateral walking. Motor imagery resulted closer to real performance in terms of timing than in terms of step length, with the exception of athletes with visual impairments that, differently from the other groups, did not show any significant differences between the numbers of imagined and performed steps. It opens a new question about the relationship between temporal and spatial imagination of locomotion.  相似文献   
310.
    
This paper focuses on the computation issue of portfolio optimization with scenario-based Value-at-Risk. The main idea is to replace the portfolio selection models with linear programming problems. According to the convex optimization theory and some concepts of ordinary differential equations, a neural network model for solving linear programming problems is presented. The equilibrium point of the proposed model is proved to be equivalent to the optimal solution of the original problem. It is also shown that the proposed neural network model is stable in the sense of Lyapunov and it is globally convergent to an exact optimal solution of the portfolio selection problem with uncertain returns. Several illustrative examples are provided to show the feasibility and the efficiency of the proposed method in this paper.  相似文献   
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