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A new approach to structural equation modeling based on so-called extended redundancy analysis (ERA) is proposed. In ERA, latent variables are obtained as exact linear combinations of observed variables, and model parameters are estimated by consistently minimizing a single criterion. As a result, the method can avoid limitations of covariance structure analysis (e.g., stringent distributional assumptions, improper solutions, and factor score indeterminacy) in addition to those of partial least squares (e.g., the lack of a global optimization procedure). The method is simple yet versatile enough to fit more complex models; e.g., those with higher-order latent variables and direct effects of observed variables. It can also fit a model to more than one sample simultaneously. Other relevant topics are also discussed, including data transformations, missing data, metric matrices, robust estimation, and efficient estimation. Examples are given to illustrate the proposed method.

Literature reports that test anxiety may have an influence on aptitude test performance for some racial groups and therefore serves as a source of bias (Zeidner, 1998). Testing organisations have also found that individuals from African groups perform poorly on measures of fluid intelligence, putting them at a disadvantage when these scores are used for selection and training purposes. The current study examines a model defining the relationship between test anxiety, attentional resources and fluid intelligence in the following manner: an increase in test anxiety will result in a decrease of attentional resources as well as a decrease in fluid intelligence. With a decrease in attentional resources we will see a negative influence on fluid intelligence and test performance for different racial groups. Twenty-five African individuals and twenty-five individuals from Caucasian racial groups have set the stage to answer the question if certain groups experience higher test anxiety and thus perform poorly on fluid intelligence measures. Significant relationships were found, within and between groups, for attentional resources and fluid intelligence. Meanwhile, other factors, such as test anxiety, were not strongly associated with fluid intelligence performance. Future research into reasons why certain racial groups display lower overall attention in testing situations is suggested in order to ensure that tests for selection and training and aptitude tests are fair to all racial groups. / Psychology / M.A. Soc. Sc.(Psychology)

published_or_final_version / abstract / Social Sciences / Doctoral / Doctor of Philosophy

In comparing the means .of two normally distributed populations with unknown variance, two tests very often used are: the two independent sample and the paired sample t tests. There is a possible gain in the power of the significance test by using the paired sample design instead of the two independent samples design.

For years attribution research has been dominated by the ANOVA model of behavior which proposes that people construct their dispositional attributions of others by carefully comparing and weighing all situational information using mental computations similar to the processes used by researchers to analyze data. A preliminary experiment successfully determined that participants were able to distinguish differences in variability assessed across persons (high vs. low consensus) and across situations (high vs. low distinctiveness). Also, it was clear that the subjects could evaluate varying levels of situational constraint. A primary experiment administered to participants immediately following the preliminary study determined that participants grossly under-utilized those same variables when making dispositional attributions. Results gave evidence against the use of traditional ANOVA models and support for the use of the Behavior Averaging Principle of Attribution. / by Kori A. Hakala. / Thesis (M.A.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

Classification algorithms represent a rich set of tools, which train a classification model from a given training and test set, to classify previously unseen test instances. Although existing methods have studied classification algorithm performance with respect to feature selection, noise condition, and sample distributions, our existing studies have not addressed an important issue on the classification algorithm performance relating to feature deletion and addition. In this thesis, we carry out sensitive study of classification algorithms by using feature deletion and addition. Three types of classifiers: (1) weak classifiers; (2) generic and strong classifiers; and (3) ensemble classifiers are validated on three types of data (1) feature dimension data, (2) gene expression data and (3) biomedical document data. In the experiments, we continuously add redundant features to the training and test set in order to observe the classification algorithm performance, and also continuously remove features to find the performance of the underlying classifiers. Our studies draw a number of important findings, which will help data mining and machine learning community under the genuine performance of common classification algorithms on real-world data. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Cheung, Yu Hin Ray. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 59-66). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

中介效應和調節效應分析在心理學研究中廣泛存在。調節效應發生時，自變量和因變量的關係的強度或方向會因調節變量的水平而有所改變。另一方面，中介效應發生時，自變量會通過中介變量對因變量來產生影響(Baron& Kenny,1986) 。心理學家經常結合這兩種效應以處理更複雜的問題，例如:調節作用是如何發生或中介作用在什麼情況會有所改變。研究學者定義前者為有中介的調節作用，後者為有調節的中介作用。儘管在文獻中有許多關於中介的調節效應和有調節的中介效應的分析方法的討論，對於理解這兩種效應的混亂仍然存在。此外，結構方程模型分析方法雖然比傳統的迴歸分析方法更靈活和有效地處理這兩種效應的分析，但是文獻上卻甚少討論如何應用結構方程模型於有中介的調節作用和有調節的中介作用的分析上。本論文回應以上提出的問題，主要討論如何把結構方程模型的分析方法應用在有中介的調節效應和有調節的中介效應的分析上，論文的第一部份會透過闡明五種常見有關於有中介的調節效應和有調節的中介效應的概念模型以消除研究橕者對這兩種效應定義的誤解。在論文的第二部分將會提出一個用以轉換有中介的調節效應和有調節的中分效應的概念模型為能應用於結構方程模型分析法上的模型的統一方法，讓研究學者能統一方法中提出的規則簡易地把假設模型變成為可為結構方程模型作分析的模型。模擬實驗來比較迴歸方法和結構方程模型方法的實際效用。結果顯示，這兩種分析方法發現相近。論文最後的部份，引人用於潛變量調節作用分析上的unconstrained indicant product approach (Marsh et al., 2004) ，並結合本文提出的統一方法來分析有中介的調節作用和有調節的中介作用，模擬實驗結果顯示這種方法在大多數的模擬情況下表現令人滿意。然而，以評估模型擬合度的卡方檢定在模擬實驗的大多數情況中都並不準確，因此研究學者應謹慎處理卡方檢定。 / Moderation and mediation analyses are widespread in psychological research. Moderation occurs when the direction and/or strength of the relation between an independent variable and a dependent variable depends on the level of a moderating variable. Mediation, on the other hand, occurs when the effect of an independent variable on a dependent variable is transmitted through a mediating variable (Baron & Kenny, 1986). Psychologists often move beyond these two processes and ask more complex questions such as how a moderating effect takes place or when a mediating process varies in different contexts. The former question has been referred as mediated moderation while the latter one has been referred as moderated mediation. Despite the fact that there are many discussions about the analysis of mediated moderation and moderated mediation in the literature, the confusion over the interpretation of these two processes persists. In addition, the SEM method, which is known to be more flexible than traditional egression method for the analysis of mediated moderation and moderated mediation is rarely discussed in the literature. In response to these issues, the main objective of the present study was to examine the methods for the analysis of mediated moderation and moderated mediation in the SEM framework. The first part of this study resolved the confusion over the current interpretation of the mediated moderation and moderated mediation by demonstrating these two processes using five typical conceptual models of mediatedmoderation and moderated mediation. In the second part, a new unified method was proposed to provide some general rules for translating the conceptual models of mediated moderation and moderated mediation into the SEM working models. The empirical performance of SEM analysis against regression analysis was assessed by a simulation study. Results showed the two methods performed similarly across different model conditions. In the last part, the unconstrained indicant product approach (Marsh, et al., 2004) for latent moderation analysis was introduced and combined with the unified approach for the analysis of latent variable mediated moderation and moderated mediation models. Simulation findings suggested that this method performed satisfactorily for testing mediated moderating and moderated mediating effects in most simulation conditions. However, chi-square statistics for the evaluation of model fit should be used with cautious as simulation results indicated that they were not accurate in most cases. / Detailed summary in vernacular field only. / Kwan, Lok Yin. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 104-114). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / ACKNOWLEDGEMENT --- p.iii / ABSTRACT --- p.v / CHINESE ABSTRACT --- p.vii / TABLE OF CONTENTS --- p.ix / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Moderation --- p.2 / Mediation --- p.2 / Moving Beyond Moderation and Mediation --- p.4 / Objectives of This Study --- p.6 / Outline of the Following Chapters --- p.8 / Chapter CHAPTER 2 --- MEDIATED MODERATION AND MODERATED MEDIATION --- p.10 / Mediated Moderation --- p.11 / Moderated Mediation --- p.13 / Critical Issues Related to the Current Interpretations --- p.14 / Moderated Mediation within a Mediation Context --- p.19 / Mediated Moderation within a Moderation Context --- p.21 / Summary of This Chapter --- p.25 / Chapter CHAPTER 3 --- ANALYSIS OF MEDIATED MODERATION AND MODERATED MEDIATION --- p.27 / Models --- p.27 / Regression-based Methods --- p.33 / Structural Equation Modeling Approach --- p.39 / A Unified Approach for Model Specification in SEM --- p.42 / Regression-based Method Versus SEM Approach --- p.49 / Chapter CHAPTER 4 --- SIMULATION STUDY 1: REGRESSION-BASED VERSUS SEM-BASED METHODS --- p.51 / Design of the Simulation Study --- p.51 / Procedure --- p.54 / Results --- p.55 / Discussion and Conclusion --- p.63 / Chapter CHAPTER 5 --- LATENT VARIABLES MEDIATED MODERATION AND MODERATED MEDATION --- p.68 / Unconstrained Indicant Product Approach --- p.69 / Model Specifications of Latent meMO and moME Models --- p.76 / Simulation Study 2: Methods --- p.83 / Simulation Study 2: Results --- p..88 / Discussion and Conclusion --- p.94 / Chapter CHAPTER 6 --- CONCLUSION AND FUTURE DIRECTION --- p.97 / Practical Significance of This Study --- p.98 / Limitations and Future Direction --- p.99 / REFERENCES --- p.104 / ENDNOTES --- p.115 / LIST OF TABLES --- p.117 / TABLES --- p.119 / FIGURE CAPTION --- p.153 / FIGURES --- p.154

Xin-Yuan Song. / "December 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 128-142). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.