Thesis (Ph.D.)--McMaster University, 2002. / Adviser: P.A. Taylor and John F. MacGregor. Includes bibliographical references. Also available via World Wide Web.

Thesis (Ph.D.)--McMaster University, 2002. / Adviser: P.A. Taylor and John F. MacGregor. Includes bibliographical references. Also available via World Wide Web.

Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2007. / Title from first page of PDF file (viewed May 29, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 99-105).

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 115-121).

One of the major challenges facing South African IT organisations today is the dramatic shortage of IT professionals. Both literature and business sentiment have indicated that employee turnover within the IT sector is on a continually rising trend. The ramifications of these high turnover rates translate into exorbitant direct and indirect costs to organisations. The purpose of this research was to identify the factors pertaining to the underlying structure of the turnover intention of these employees. A deeper understanding of these drivers may possibly enable management to reduce the turnover intention of employees within their organisations. A quantitative, multi-disciplinary research approach, focussing on the antecedents of turnover intention and the three systemic levels of organisational behaviour (micro, meso and macro) was used to operationalise the main research construct of this study. Data was collected by means of an anonymous self-administered web-based survey. A sample of 188 completed questionnaires was collected using a snowball sampling technique from the population of employees in the IT industry in South Africa. A statistical data reduction method, exploratory factor analysis, was conducted on the dataset to determine the underlying nature of the construct, IT employees’ perceived intention to resign from employment. After an appropriate number of factor analytic rounds, a robust 4-factor model of the data set was established. The results indicated that the factor, Personal Enrichment from Management Support, possibly plays the most significant role in understanding, monitoring, and managing IT employees’ perceived intention to resign from employment. The study provided support that monetary factors had the most significant influence in an employee’s decision to join an organisation; however, nonmonetary benefits, such as job satisfaction and skills development, were found to be more effective in retaining employees. The practical implications uncovered from this study will enable management to gain further insight into understanding the underlying factors and drivers of turnover intention and thereby minimise its impact on the organisation. / Dissertation (MBA)--University of Pretoria, 2013. / lmgibs2014 / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted

Les délinquants sexuels sadiques sont généralement décrits comme une entité clinique particulière commettant des délits graves. Or, la notion même de sadisme sexuel pose un nombre important de problèmes. Parmi ceux-ci, on retrouve des problèmes de validité et de fidélité. Perçu comme une maladie dont on est atteint ou pas, le sadisme a été étudié comme si les sadiques étaient fondamentalement différents. À l’heure actuelle, plusieurs travaux laissent croire que la majorité des troubles psychologiques se présentent comme une différence d'intensité (dimension) plutôt qu’une différence de nature (taxon). Même si la conception médicale prévaut encore en ce qui concerne le sadisme sexuel, plusieurs évoquent l’idée qu’il pourrait être mieux conceptualisé à l’aide d’une approche dimensionnelle. En parallèle, nos connaissances sur les facteurs contributifs au développement du sadisme sexuel sont limitées et reposent sur de faibles appuis empiriques. Jusqu'à présent, très peu d'études se sont intéressées aux facteurs menant au développement du sadisme sexuel et encore moins ont tenté de valider leurs théories. En outre, nos connaissances proviennent majoritairement d'études de cas portant sur les meurtriers sexuels, un sous-groupe très particulier de délinquants fréquemment motivé par des intérêts sexuels sadiques. À notre connaissance, aucune étude n'a proposé jusqu'à présent de modèle développemental portant spécifiquement sur le sadisme sexuel. Pourtant, l'identification de facteurs liés au développement du sadisme sexuel est essentielle dans notre compréhension ainsi que dans l'élaboration de stratégie d'intervention efficace. La présente thèse s'inscrit dans un contexte visant à clarifier le concept de sadisme sexuel. Plus spécialement, nous nous intéressons à sa structure latente, à sa mesure et à ses origines développementales. À partir d'un échantillon de 514 délinquants sexuels évalué au Massachusetts Treatment Center, la viabilité d’une conception dimensionnelle du sadisme sexuel sera mise à l’épreuve à l'aide d'analyses taxométriques permettant d'étudier la structure latente d'un construit. Dans une seconde étape, à l'aide d'analyses de Rasch et d'analyses appartenant aux théories de la réponse à l'item à deux paramètres, nous développerons la MTC Sadism Scale (MTCSS), une mesure dimensionnelle du sadisme sexuel. Dans une troisième et dernière étape, un modèle développemental sera élaboré à l'aide d'équations structurales. La présente thèse permettra de contribuer à la clarification du concept de sadisme sexuel. Une clarification de la structure latente et des facteurs développementaux permettra de saisir les devis de recherche les plus à même de capturer les aspects essentiels. En outre, ceci permettra d'identifier les facteurs pour lesquels une intervention est la plus appropriée pour réduire la récidive, ou la gravité de celle-ci. / Sadistic offenders are generally described as a particular clinical entity committing serious offenses. However, the very notion of sexual sadism is plague with a significant number of problems. Among these, there are important problems of validity and reliability. Perceived as a disease which one can or can't have, sadism was studied as if sadistic offenders were fundamentally different from non-sadistic offenders. Actually, several studies suggest that the majority of psychological disorders present a dimensional rather that a taxonic structure. Therefore, the difference between two individuals will be a difference of intensity instead of nature. Although the medical conceptualization still prevails regarding sexual sadism, many evoke the idea that it might be best conceptualized using a dimensional approach. On the other hand, our knowledge on the factors leading to the development of sexual sadism are based on weak empirical foundations. So far, very few studies have examined the factors leading to the development of sexual sadism and even fewer have attempted to validate their theories. In addition, our knowledge mainly comes from case studies of sexual murderers, some of whom exhibit an extreme form of sexual sadism. To our knowledge, no study has proposed a developmental model of sexual sadism. The identification of factors associated with the development of sexual sadism is essential in our understanding of this paraphilia and in the development of effective intervention strategies. The aim of the present thesis is to clarify the concept of sexual sadism. Specifically, we are interested in its latent structure, its assessment and its developmental origins. From a sample of 514 sexual offenders assessed at the Massachusetts Treatment Center, the viability of a dimensional conception of sexual sadism will be tested using taxometrics analyses. In a second step, using Rasch analyses and two-parameters item response theory analyses, we will develop the MTCSS, a dimensional measure of sexual sadism. In a third and final stage, a developmental model of sexual sadism will be developed using structural equations analyses. The current thesis will contribute significantly to the clarification of the concept of sexual sadism. A clarification of its latent structure and developmental factors will allow to develop better research designs to capture the essential aspects of sexual sadism. In addition, this will allow to identify the factors for which intervention is the most appropriate to reduce recidivism, or the severity of it.

Scene understanding attempts to produce a textual description of visible and latent concepts in an image to describe the real meaning of the scene. Concepts are either objects, events or relations depicted in an image. To recognize concepts, the decision of object detection algorithm must be further enhanced from visual similarity to semantical compatibility. Semantically relevant concepts convey the most consistent meaning of the scene. Object detectors analyze visual properties (e.g., pixel intensities, texture, color gradient) of sub-regions of an image to identify objects. The initially assigned objects names must be further examined to ensure they are compatible with each other and the scene. By enforcing inter-object dependencies (e.g., co-occurrence, spatial and semantical priors) and object to scene constraints as background information, a concept classifier predicts the most semantically consistent set of names for discovered objects. The additional background information that describes concepts is called context. In this dissertation, a framework for building context-based concept detection is presented that uses a combination of multiple contextual relationships to refine the result of underlying feature-based object detectors to produce most semantically compatible concepts. In addition to the lack of ability to capture semantical dependencies, object detectors suffer from high dimensionality of feature space that impairs them. Variances in the image (i.e., quality, pose, articulation, illumination, and occlusion) can also result in low-quality visual features that impact the accuracy of detected concepts. The object detectors used to build context-based framework experiments in this study are based on the state-of-the-art generative and discriminative graphical models. The relationships between model variables can be easily described using graphical models and the dependencies and precisely characterized using these representations. The generative context-based implementations are extensions of Latent Dirichlet Allocation, a leading topic modeling approach that is very effective in reduction of the dimensionality of the data. The discriminative contextbased approach extends Conditional Random Fields which allows efficient and precise construction of model by specifying and including only cases that are related and influence it. The dataset used for training and evaluation is MIT SUN397. The result of the experiments shows overall 15% increase in accuracy in annotation and 31% improvement in semantical saliency of the annotated concepts. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

[pt] O objetivo do presente trabalho consistia em traduzir o Questionário de Preocupação do Estado da Pensilvânia (PSWQ) para o português e avaliar as propriedades psicométricas e a estrutura latente desta versão traduzida em uma amostra representativa de universitários no Brasil para determinar sua confiabilidade e validade psicométricas. Um primeiro estudo utilizou 871 graduandos de diferentes Universidades do Rio de Janeiro apresentando uma faixa de idade de 17 a 68 anos. Uma análise fatorial exploratória (AFE) foi realizada para examinar a estrutura latente dos 16 itens que compõem esta escala. Um segundo estudo utilizou 978 graduandos com as mesmas características do estudo 1. Uma análise fatorial confirmatória (AFC) foi usada para inspecionar eventuais artefatos fatoriais da escala, previamente descritos na literatura. Os resultados indicaram que o PSWQ apresentou uma adequada consistência interna. No primeiro estudo, uma AFE indicou uma solução de dois fatores. Um fator foi relacionado com a preocupação presente e incorporou todos os 11 itens escritos na forma afirmativa. O outro foi associado com a preocupação ausente e incorporou todos os 5 itens escritos na forma negativa. No segundo estudo, uma AFC ajustou uma solução de três fatores. Um fator incorporou todos os itens do PSWQ, onde os outros dois fatores foram relacionados com os itens na afirmativa e negativa. Coeficientes de correlação destes dois fatores de itens na afirmativa e negativa com o total do PSWQ e a subescala traço do Inventário de Ansiedade Traço-Estado sugerem que o fator composto pelos 5 itens na negativa não contribui significativamente para a estrutura latente do PSWQ. A avaliação psicométrica da versão em português do PSWQ indicou que esta escala pode medir confiavelmente a presença do construto de preocupação em uma amostra não clínica. Análises de sua estrutura fatorial sugeriram que o fator da preocupação ausente deve ser um artefato metodológico atribuído ao efeito da forma escrita dos itens na negativa. / [en] Translate the Penn State Worry Questionnaire (PSWQ) to Portuguese and evaluate the psychometric properties and the latent structure of the translated version in a large Brazilian college student sample to determine its psychometric reliability and validity. A first study employed 871 undergraduate students from different Universities of Rio de Janeiro ranging from 17 to 68 years of age. An exploratory factor analysis (EFA) was employed to analyze its latent structure of 16 items that composes the scale. A second study employed 978 college students with the same characteristics from Study 1. A confirmatory factor analysis (CFA) was used to investigate eventual factorial artifacts of the scale previously described in the literature. Results indicated that PSWQ had an adequate internal consistency. In the first study, the EFA yields a two-factor solution. One factor was related to worry presence and incorporated all the 11 positive-worded items stated in a non-reversed form. The other was associated to worry absence and incorporated all the five negative- worded items stated in a reversed form. In a second study, the CFA leads to a three- factor solution. One factor incorporated all the PSWQ items whereas the two other factors were linked to the reversed and non-reversed items. Correlations coefficients of these two reversed and non-reversed factors with the total scores of the PSWQ and the trait subscale of the State-Trait Anxiety Inventory suggest that the factor composed by the five items do not contribute in a meaningful way to the PSWQ latent structure. Psychometric evaluation of the Portuguese version of the PSWQ indicated that the scale can reliably measure the presence of the worry construct in a non-clinical sample. Analysis of its factorial structure suggested that the worry absence factor might be a methodological artifact due to a wording effect of the reversed items.

In this study systems thinking approaches were applied to uncover the structure of the e-learning practitioner construct. Assumptions abducted from the systemic view of the e-learning practitioner construct hold that the e-learning practitioner system involves the e-learning practitioner and the e-learning practice as two subsystems that interact in the e-learning work environment. The characteristics of the subsystems are patterned to reflect their respective structures, which collaboratively construe the structure of the e-learning practitioner system. Different lenses were used to take ’snapshots’ and to illuminate the separate parts (the environment, the e-learning practitioner and the e-learning practice) of the system and to tell the e-learning practitioner’s story. Work behavioural styles expressed in terms of DISC language were used to describe a particular aspect of work personality structure. A personality-orientated job analysis, namely the Human Job Analysis, was used to identify and describe job characteristics and job structure. Person characteristics from the individual and characteristics from the job are the inputs into the e-learning practitioner system, and through a process of reciprocal interaction lead to certain outputs, for example person-job (P-J) fit, moderated by environmental influences, and constantly monitored by feedback systems. Environmental changes act as drivers in the system and practical interventions, such as the implementation of support programmes, job redesign and career development, may be applied as leverage points to change the output, for example to create a number of P-J fit scenarios. The characteristics of each subsystem and their relationships form the building blocks of the system structured in an e-learning P-J fit triad. Triad congruence is dependent on the characteristics of each leg of the triad, as well as influences and drivers from the environment. The different parts work together towards a specific goal according to a specific plan driven by organising principles to fulfil a common purpose, which gives meaning to the system. Different scenarios may alter the congruence of these three legs, which may then emerge in different configurations from their latent position. To gain a better understanding of this construct, a case study was applied focusing on the characteristics and work behavioural styles of e-learning practitioners in the e-learning work environment at the Tshwane University of Technology. A bricolage of data collection methods and instruments was applied to collect evidence for answering the research questions. Rich and varied sources of data, for example interviews, participant observation, documents and archival records, were tapped during the data collection phase. Data analysis included quantitative and qualitative analysis, and reasoning though both inductive and abductive logic. Synthesis of these research findings resulted in a classifying scheme as a form for expressing the latent structure of the five possible e-learning scenarios to answer the main research question: “What is the latent structure of the e-learning practitioner construct?” The study focused on the creation of knowledge about the ‘goodness of fit’ between the e-learning practitioner and the e-learning job in the e-learning environment by using the combined languages of systems thinking and the DISC profiling system. The uniqueness of this study pertains to the following: -- the interplay between the characteristics of e-learning practitioners, the e-learning practice and the e-learning environment; -- P-J fit scenarios in the e-learning environment, and -- a classification scheme for the e-learning practitioner construct displaying five categories, namely job structure, job theme, person attributes, roles and applications against the dimensions of an environmental structuredness continuum. Findings from this research may support initiatives to establish benchmarks for the e-learning practitioner job description. Practical applications may be useful to practitioners using electronic learning management systems and to planners of staff development and e-learning training programmes. / Thesis (PhD (Curriculum Studies))--University of Pretoria, 2007. / Curriculum Studies / unrestricted

Traditional latent class analysis (LCA) considers entropy R2 as the only measure of effect size. However, entropy may not always be reliable, a low boundary is not agreed upon, and good separation is limited to values of greater than .80. As applications of LCA grow in popularity, it is imperative to use additional sources to quantify LCA classification accuracy. Greater classification accuracy helps to ensure that the profile of the latent classes reflect the profile of the true underlying subgroups. This Monte Carlo study compared the quantification of classification accuracy and confidence intervals of three effect sizes, entropy R2, I-index, and Cohen’s d. Study conditions included total sample size, number of dichotomous indicators, latent class membership probabilities (γ), conditional item-response probabilities (ρ), variance ratio, sample size ratio, and distribution types for a 2-class model. Overall, entropy R2 and I-index showed the best accuracy and standard error, along with the smallest confidence interval widths. Results showed that I-index only performed well for a few cases.