Over the past two decades there has been an upsurge in interest in structural equation modelling (SEM). Applications abound in the social sciences and econometrics, but the use of this multivariate technique is not so common in public health research. This dissertation discusses the methodology, the criticisms and practical problems of SEM. We examine actual applications of SEM in public health research. Comparisons are made between multiple regression and SEM and between factor analysis and SEM. A complex model investigating the utilization of antenatal care services (ANC) by migrant women in Belgium is analysed using SEM. The dissertation concludes with a discussion of the results found and on the use of SEM in public health research. Structural equation modelling is recommended as a tool for public health researchers with a warning against using the technique too casually. / Mathematical Sciences / M. Sc. (Statistics)

Among the many promises of the revolution in the information and communication technologies (ICT), particularly the Internet, continues to be its potential to significantly transform governments around the world. This transformation is referred to as e-government or web-based government, often used interchangeably in most of the IS literature. Despite these however, the level of adoption and use of such innovation is still low and does not meet expectations in developing countries in general and Jordan in particular. Yet, existing research on the adoption and implementation of e-government in developing countries is still lacking explanatory power for the following reasons: 1) focusing either on the supply-side, or on the demand-side separately to study the adoption and implementation of e-government, and therefore there is no enough research on the integration between them as a single phenomenon, and 2) focusing on the results of previous research, and therefore not to develop theories fit the new context to be investigated to understand the relationship between the IT implementation and social structures in the same context. This research aims to fill these gaps through the use of a holistic approach to enable in-depth understanding and gain valuable insights on the adoption and implementation of e-government from multiple perspectives, and in the real context of a developing country, namely Jordan. This would reduce the gap between government strategies and policies related to implementation of e-government services and applications on the one hand, and perceptions of citizens on the other hand, allowing a better understanding of the needs of citizens and the priorities that must be taken into account by governments in order to ensure the success of such projects on a large scale. Through two phases, this research proposes and empirically tests an integrated model of the determinants of adoption and implementation of e-government services and applications in Jordan. The first phase employs a grounded theory methodology for the development of the research model, as well as the survey instruments necessary to test the model. The second phase employs a survey questionnaire to test the research model using multivariate and SEM with the results demonstrating support for the proposed model. The empirical results indicate that perceived ease of use, perceived usefulness, and the security of e-government systems are no longer among the main determinants that affect the decision to adopt and implement e-government services and applications in this particular context. This confirms that the prevailing models and theories on the adoption of IT do not apply equally to the context of developing countries such as Jordan, and thus do not explain and predict behaviour toward the adoption and implementation of e-government services and applications in the same context. There is a direct and positive relationship between citizen involvement in the change process towards e-government and the decision to adopt and implement e-government services and applications. There is also a strong positive relationship between the decision to adopt and implement e-government services and applications and the decision to use such services and applications within the same context. Unexpectedly, the prevailing sociocultural determinants indicate a direct and positive relationship with the decision to adopt and implement e-government services and applications in the same context. Also, the results indicate direct and negative relationships between citizen trust and website design issues with the decision to adopt and implement e-government services and applications. Finally, the research concludes by highlighting the theoretical and practical implications, limitations and future directions.

With educational effectiveness studies, school-level aggregates of students' characteristics (e.g. achievement) are often used to assess the impact of school composition on students' outcomes – school compositional effects. Empirical findings on the magnitude and direction of school compositional effects have not been consistent. Relevant methodological studies raise the issue of under-specification at level 1 in compositional models - evident when the student-level indicator on which the aggregation is based is mis-measured. This phenomenon has been shown to bias compositional effect estimates, leading to misleading effects of the aggregated variables – phantom compositional effects. My thesis, consisted of three separate studies, presents an advanced methodological framework that can be used to investigate the effect of school composition net of measurement error bias. In Study 1, I quantify the impact of failing to account for measurement error on school compositional effects as used in value added models of educational effectiveness to explain relative school effects. Building on previous studies, multilevel structural equation models are incorporated to control for measurement error and/or sampling error. Study 1a, a large sample of English primary students in years one and four (9,059 students from 593 schools) reveals a small, significant and negative compositional effect on students' subsequent mathematics achievement that becomes more negative after controlling for measurement error. Study 1b, a large study of Cyprus primary students in year four (1694 students in 59 schools) shows a small, positive but statistically significant effect that becomes non-significant after controlling for measurement error. Further analyses with the English data (Study 2), demonstrates a negative compositional effect of school average mathematics achievement on subsequent mathematics self-concept – a Big Fish Little Pond Effect (BFLPE). Adjustments for measurement and sampling error result in more negative BFLPEs. The originality of Study 2 lies in verifying BFLPEs for students as young as five to eight/nine years old. Bridging the findings related to students' mathematics self-concept (Study 2) and the findings on students’ mathematics achievements (Study 1a), I demonstrate that the prevalence of BFLPEs with the English data partly explains the negative compositional effect of school average mathematics achievement on students' subsequent mathematics achievement. Lastly, in Study 3 I consider an alternative approach to school accountability to conventional value added models, namely the Regression Discontinuity approach. Specifically, I use the English TIMSS 1995 primary (years four and five) and secondary (years eight and nine) data to investigate the effect of one extra year of schooling on students' mathematics achievement and the variability across schools in their absolute effects. The extent to which school composition, as given by school average achievement, correlates with schools' added-year effects is addressed. Importantly the robustness of the RD estimates to measurement error bias is demonstrated. My findings have important methodological, substantive and theoretical implications for on-going debates on the school compositional effects on students' outcomes, because nearly all previous research has been based on traditional approaches to multilevel models, which are positively biased due to the failure to control for measurement error.

The research was aimed at addressing the challenge of evaluating a large scale change intervention in a large organisation and in a complex environment. Finding robust, meaningful yet realistic methodologies from among the array of possible approaches, methods and techniques has proved problematic, for both organisational practitioners and academics alike. The research explored this issue of choice from the perspective of ¿fit for purpose¿ and suggests a multi-faceted approach, using a range of evaluation methods and techniques, which were applied to an ongoing example at the BBC. It was also planned to use structural equation modelling (SEM) techniques to examine the relationships between variables critical to the study. The approach described represents a ¿pilot¿ evaluation exercise, which drew on data collected from early cohorts going through the BBC Leadership Programme, a key element of the ¿Making it Happen¿ change strategy initiated by the then Director General, Mr. Greg Dyke. As a second level of research, an evaluation of the primary evaluation itself, i.e. of the BBC Leadership Programme, was also undertaken to assess the effectiveness of the primary evaluation strategy and its implementation. Three hypotheses were examined in terms of programme impact: It was proposed that participation in the programme would bring about collective improvements in individual leadership behaviour (Ho1), leading to improved departmental performance across the business (Ho2), in turn, resulting in improved organisational performance (Ho3). Due to limitations in the application of the methodology it was not possible to use SEM analyses on the data collected. Alternative analyses failed to demonstrate conclusive support for all three hypotheses and, while other factors besides programme attendance appear to influence leadership performance the afore-mentioned limitations restrict the ability to draw firm conclusions. Following evaluation of the primary evaluation it was evident that, as a pilot exercise, important outcomes from the programme evaluation give rise to ¿lessons learned¿ and changes are suggested for any future evaluation exercise of this kind.

The research was aimed at addressing the challenge of evaluating a large scale change intervention in a large organisation and in a complex environment. Finding robust, meaningful yet realistic methodologies from among the array of possible approaches, methods and techniques has proved problematic, for both organisational practitioners and academics alike. The research explored this issue of choice from the perspective of 'fit for purpose' and suggests a multi-faceted approach, using a range of evaluation methods and techniques, which were applied to an ongoing example at the BBC. It was also planned to use structural equation modelling (SEM) techniques to examine the relationships between variables critical to the study. The approach described represents a 'pilot' evaluation exercise, which drew on data collected from early cohorts going through the BBC Leadership Programme, a key element of the 'Making it Happen' change strategy initiated by the then Director General, Mr. Greg Dyke. As a second level of research, an evaluation of the primary evaluation itself, i.e. of the BBC Leadership Programme, was also undertaken to assess the effectiveness of the primary evaluation strategy and its implementation. Three hypotheses were examined in terms of programme impact: It was proposed that participation in the programme would bring about collective improvements in individual leadership behaviour (Ho1), leading to improved departmental performance across the business (Ho2), in turn, resulting in improved organisational performance (Ho3). Due to limitations in the application of the methodology it was not possible to use SEM analyses on the data collected. Alternative analyses failed to demonstrate conclusive support for all three hypotheses and, while other factors besides programme attendance appear to influence leadership performance the afore-mentioned limitations restrict the ability to draw firm conclusions. Following evaluation of the primary evaluation it was evident that, as a pilot exercise, important outcomes from the programme evaluation give rise to 'lessons learned' and changes are suggested for any future evaluation exercise of this kind.

No description available.

Work stress has a substantial impact on employees, organisations and economies; especially in the fragile economic environment since the ‘Great Recession’ of 2008; which has seen employment levels drop and employees willing to endure more stress at work to avoid retrenchment. These impacts include serious health and financial consequences. Attempts should therefore be made to effectively manage and address work stress to lessen these dire consequences. Many models have been developed and theorised to assist in explaining work stress, the pinnacle of these being the job demands-resources (JD-R) model. In JD-R theory, the dual process explains that work-related well-being follows the following processes: An energetic, also called the health impairment process, in which job demands leads to ill health outcomes through burnout; and then a motivational process which presents that job resources leads to positive organisational outcomes, e.g. organisational commitment, through engagement. The main objectives of this research were 1) to investigate a JD-R model in a large South African sample with a categorical estimator; 2) to investigate the reversed causal hypotheses of burnout and engagement in job demands-resources theory over time; 3) to investigate the likelihood of reporting treatment for health conditions based on burnout and engagement, and 4) to investigate the link between burnout and objective financial outcomes, i.e. by medical aid provider expenditure. To achieve the first objective a cross-sectional design was used (n = 15 633) covering numerous sectors in South Africa. A dual process model was specified with job demands (work overload) leading to ill health through burnout, and job resources (colleague and supervisor support, communication, growth opportunities and role clarity) leading to organisational commitment through engagement. Results of structural equation modelling indicated that the proposed JD-R model was a good fit to the sample. Furthermore, burnout was found to mediate the relationship between job demands and ill health with a medium effect. Engagement was found to mediate the relationship between job resources and organisational commitment with a large effect. The second objective, concerning reversed causality, was achieved with a longitudinal design (n = 593). The hypothesized model included burnout and engagement at time one, and at time two work overload as indicator of job demands, and colleague and supervisor support, communication, growth opportunities and role clarity as indicators of job resources. Results indicated that burnout had a significant negative reversed causal effect to supervisor support and colleague support. Engagement showed only one significant result, i.e. a small negative reversed causal relationship with supervisor support. To achieve the third objective, a cross-sectional design was used (n = 7 895). Results for logistic regression analyses showed that an increase in burnout was associated with a significant increase in the estimated odds for reporting an affirmative answer for receiving treatment for any of the health conditions, i.e. cardiovascular conditions, cholesterol, depression, diabetes, hypertension and irritable bowel syndrome. In contrast, an increase in engagement was associated with a decrease in affirmative reporting for cardiovascular conditions, cholesterol and depression; but not for diabetes, hypertension or irritable bowel syndrome. Addressing the link between burnout and financial outcomes was the fourth objective; and met with a cross-sectional design (n = 3 182). Participants were divided into a high and low burnout group based on the comorbidity of exhaustion and cynicism Analysis of covariance (ANCOVA) was implemented, controlling for age and gender, to investigate the difference in medical aid provider expenditure of the two groups. Results revealed that expenditure in the high burnout group was consistently more in all cases, compared to the low burnout group. By way of conclusion, the implications of the research were discussed and recommendations for managers and for future research were made. / Thesis (PhD (Industrial Psychology))--North-West University, Potchefstroom Campus, 2013

Work stress has a substantial impact on employees, organisations and economies; especially in the fragile economic environment since the ‘Great Recession’ of 2008; which has seen employment levels drop and employees willing to endure more stress at work to avoid retrenchment. These impacts include serious health and financial consequences. Attempts should therefore be made to effectively manage and address work stress to lessen these dire consequences. Many models have been developed and theorised to assist in explaining work stress, the pinnacle of these being the job demands-resources (JD-R) model. In JD-R theory, the dual process explains that work-related well-being follows the following processes: An energetic, also called the health impairment process, in which job demands leads to ill health outcomes through burnout; and then a motivational process which presents that job resources leads to positive organisational outcomes, e.g. organisational commitment, through engagement. The main objectives of this research were 1) to investigate a JD-R model in a large South African sample with a categorical estimator; 2) to investigate the reversed causal hypotheses of burnout and engagement in job demands-resources theory over time; 3) to investigate the likelihood of reporting treatment for health conditions based on burnout and engagement, and 4) to investigate the link between burnout and objective financial outcomes, i.e. by medical aid provider expenditure. To achieve the first objective a cross-sectional design was used (n = 15 633) covering numerous sectors in South Africa. A dual process model was specified with job demands (work overload) leading to ill health through burnout, and job resources (colleague and supervisor support, communication, growth opportunities and role clarity) leading to organisational commitment through engagement. Results of structural equation modelling indicated that the proposed JD-R model was a good fit to the sample. Furthermore, burnout was found to mediate the relationship between job demands and ill health with a medium effect. Engagement was found to mediate the relationship between job resources and organisational commitment with a large effect. The second objective, concerning reversed causality, was achieved with a longitudinal design (n = 593). The hypothesized model included burnout and engagement at time one, and at time two work overload as indicator of job demands, and colleague and supervisor support, communication, growth opportunities and role clarity as indicators of job resources. Results indicated that burnout had a significant negative reversed causal effect to supervisor support and colleague support. Engagement showed only one significant result, i.e. a small negative reversed causal relationship with supervisor support. To achieve the third objective, a cross-sectional design was used (n = 7 895). Results for logistic regression analyses showed that an increase in burnout was associated with a significant increase in the estimated odds for reporting an affirmative answer for receiving treatment for any of the health conditions, i.e. cardiovascular conditions, cholesterol, depression, diabetes, hypertension and irritable bowel syndrome. In contrast, an increase in engagement was associated with a decrease in affirmative reporting for cardiovascular conditions, cholesterol and depression; but not for diabetes, hypertension or irritable bowel syndrome. Addressing the link between burnout and financial outcomes was the fourth objective; and met with a cross-sectional design (n = 3 182). Participants were divided into a high and low burnout group based on the comorbidity of exhaustion and cynicism Analysis of covariance (ANCOVA) was implemented, controlling for age and gender, to investigate the difference in medical aid provider expenditure of the two groups. Results revealed that expenditure in the high burnout group was consistently more in all cases, compared to the low burnout group. By way of conclusion, the implications of the research were discussed and recommendations for managers and for future research were made. / Thesis (PhD (Industrial Psychology))--North-West University, Potchefstroom Campus, 2013

Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2017-12-08T12:19:49Z No. of bitstreams: 1 PGEF16MA060.pdf: 200273 bytes, checksum: c59f22cc1e5f18c0272f4b828aab3423 (MD5) / Made available in DSpace on 2017-12-08T12:19:50Z (GMT). No. of bitstreams: 1 PGEF16MA060.pdf: 200273 bytes, checksum: c59f22cc1e5f18c0272f4b828aab3423 (MD5) Previous issue date: 2016-02-26 / Capes / This work aimed to evaluate the influence of landscape structure on the floristic-structural organization and the demographics rates of the tree component of Araucaria Forest fragments in South Plateau of Santa Catarina State, in Brazil. Studies of this nature are important to the development of conservation strategies in fragmented landscapes, situation of the study area. Two chapters are presented, in the first i) the influence of landscape structure on the floristic-structural patterns in forest fragments was analyzed; and in the second ii) the inter-relationships between the landscape spatial configuration x floristic-structural organization x demographics rates of tree component were verified in a system formed by forest fragments and corridors. For nine forest fragments in the region, surrounding land cover maps and landscape metrics (shape, connectivity and influence of edge) were generated from the Landsat 8 satellite images; and information about floristic-structural composition of tree component was obtained. For the forest fragment-corridor system the demographics rates for a four years period (2010-2014) were also obtained. The data were analyzed through Principal Component Analysis (PCA), Non-Metric Multidimensional Scaling (NMDS), Principal Coordinates Analysis (PCoA), Structural Equations Models, and Generalized Linear Models (GLM). In the first chapter, it was observed that the spatial configuration of the fragments in the landscape (shape complexity and area) and the surrounding land cover (forest, swamp, grassland, urbanization) significantly influenced the floristic-structural organization of the arboreal vegetation. In the second chapter, it was evidenced that the floristic-structural organization of the tree component was influenced by landscape spatial configuration and the tree abundance; and the demographics rates were only influenced by 14 vegetation structure (abundance and basal area). We conclude that the landscape spatial configuration influences the floristic-structural organization in FOM areas and that demographic rates of the tree component are determined primarily by structural aspects, which reflect the successional stage of vegetation / A presente dissertação objetivou avaliar a influência da estrutura da paisagem sobre a organização florística-estrutural e sobre as taxas demográficas do componente arbóreo de fragmentos de Floresta Ombrófila Mista (FOM) no Planalto Sul Catarinense. Estudos dessa natureza são importantes para o desenvolvimento de estratégias de conservação em paisagens fragmentadas, situação em que se encontra a região de estudo. São apresentados dois capítulos, sendo que no primeiro i) foi analisada a influência da estrutura da paisagem sobre os padrões florístico-estruturais em fragmentos florestais; e no segundo ii) foram verificadas as inter-relações entre a configuração espacial da paisagem x organização florística-estrutural x taxas demográficas do componente arbóreo, em um sistema composto por fragmentos e corredores florestais. Para nove remanescentes florestais na região, foram gerados mapas de cobertura do solo no entorno e obtidas as métricas de paisagem de área (forma, conectividade, influência de borda e área das classes de cobertura na vizinhança), a partir de imagens do satélite Landsat 8; e obtidas informações sobre a composição florística-estrutural, além das taxas demográficas do sistema de fragmentos e corredores para um período de quatro anos (2010-2014). Os dados foram analisados por meio de Análise de Componentes Principais (PCA), Escalonamento Multidimensional Não-Métrico (NMDS), Análise de Coordenadas Principais (PCoA), Modelagem de Equações Estruturais e Modelos Lineares Generalizados (GLM). No primeiro capítulo, observou-se que a configuração espacial dos fragmentos na paisagem (complexidade da forma e área) e a cobertura do solo do entorno (floresta, banhado, campo, urbanização) influenciaram de forma significativa a organização florística-estrutural da vegetação arbórea. No segundo capítulo ficou evidenciado que a organização 12 florística-estrutural do componente arbóreo foi influenciada pela configuração espacial da paisagem e pela a abundância de árvores, e as taxas demográficas foram influenciadas apenas por aspectos estruturais (abundância e área basal) da vegetação. Conclui-se que a configuração espacial da paisagem exerce influência sobre a organização florística-estrutural em áreas de FOM e que as taxas demográficas do componente arbóreo são determinadas fundamentalmente por aspectos estruturais, que refletem o estágio sucessional da vegetação

Police officers provide emergency services to the public, while being simultaneously exposed to various organisational and social stressors over which they have little or no control. The outcome of this may be that highly committed and loyal police officers become psychologically and physically burned-out. Adversely, others may accept the same conditions and situations as a challenge and live an energetic and proactive life while experiencing a positive affective state (vigour) toward their duties. Officers who are burned-out may fail to meet their goal to protect the public, but eventually may suffer. The general objective of this study was to investigate vigour and burnout as obliquely related outcomes of the stress and coping process in terms of its dynamic relationship with challenges or threats, and the mediating role of personal factors, social resources and coping resources in the police context. The research is a qualitative explication of theoretical concepts and constructs, followed by a quantitative empirical survey design. The survey led to a Structural Equation Model (SEM) fit between empirical data and the Moos (1994) hypothesised stress and coping model. Seven measuring instruments were used to collect data. Job demands, work overload and uncertainty were identified as causes of work stress originating within the work situation. Respondents indicated that family members play a role in social support, although it decreases when stress increases. The SEM procedure revealed that social support and personality has a limited and direct effect on well-being when experiencing a positive affective state (vigour), with coping strategies deleted from the experimental model. Adversely, stress has a direct effect on well-being (and eventually burnout) with no moderating effects by the hypothesised variables. The study proposes a new Police Vigour and Burnout Model (PVBM) as an alignment to the Moos (1994) model. It is recommended that vigour and burnout, as outcomes of the stress and coping process, be included in future studies as obliquely related variables in other spheres of society. An additional proposal is that stress inducing features within the police organisation should be scrutinized and critically addressed to prevent negative psychological affects. / Industrial Psychology / D.Litt. et Phil. (Industrial and Organisational Psyschology)