Matching Items (16)
Description
In investigating mediating processes, researchers usually use randomized experiments and linear regression or structural equation modeling to determine if the treatment affects the hypothesized mediator and if the mediator affects the targeted outcome. However, randomizing the treatment will not yield accurate causal path estimates unless certain assumptions are satisfied. Since randomization of the mediator may not be plausible for most studies (i.e., the mediator status is not randomly assigned, but self-selected by participants), both the direct and indirect effects may be biased by confounding variables. The purpose of this dissertation is (1) to investigate the extent to which traditional mediation methods are affected by confounding variables and (2) to assess the statistical performance of several modern methods to address confounding variable effects in mediation analysis. This dissertation first reviewed the theoretical foundations of causal inference in statistical mediation analysis, modern statistical analysis for causal inference, and then described different methods to estimate causal direct and indirect effects in the presence of two post-treatment confounders. A large simulation study was designed to evaluate the extent to which ordinary regression and modern causal inference methods are able to obtain correct estimates of the direct and indirect effects when confounding variables that are present in the population are not included in the analysis. Five methods were compared in terms of bias, relative bias, mean square error, statistical power, Type I error rates, and confidence interval coverage to test how robust the methods are to the violation of the no unmeasured confounders assumption and confounder effect sizes. The methods explored were linear regression with adjustment, inverse propensity weighting, inverse propensity weighting with truncated weights, sequential g-estimation, and a doubly robust sequential g-estimation. Results showed that in estimating the direct and indirect effects, in general, sequential g-estimation performed the best in terms of bias, Type I error rates, power, and coverage across different confounder effect, direct effect, and sample sizes when all confounders were included in the estimation. When one of the two confounders were omitted from the estimation process, in general, none of the methods had acceptable relative bias in the simulation study. Omitting one of the confounders from estimation corresponded to the common case in mediation studies where no measure of a confounder is available but a confounder may affect the analysis. Failing to measure potential post-treatment confounder variables in a mediation model leads to biased estimates regardless of the analysis method used and emphasizes the importance of sensitivity analysis for causal mediation analysis.
ContributorsKisbu Sakarya, Yasemin (Author) / Mackinnon, David Peter (Thesis advisor) / Aiken, Leona (Committee member) / West, Stephen (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2013
Description
Research suggests that a particularly important variable in determining success in public participation is the presence of a facilitator. Data from a study of 239 public participation case studies is analyzed using descriptive and statistical analysis to determine the impact on success of the participation efforts if a facilitator is present and whether or not internal versus external facilitators have a significant impact on success. The data suggest that facilitators have a positive impact on the success of public participation efforts and, in particular, that public participation efforts that use facilitators are more successful when the facilitator is a third-party intermediary (external) versus a member of the lead agency's staff (internal).
ContributorsWastchak, Daran Reginald (Author) / Cayer, Joseph (Thesis advisor) / Lucio, Joanna (Committee member) / Schugurensky, Daniel, 1958- (Committee member) / Arizona State University (Publisher)
Created2013
Description
Research on Tyler’s process-based model has found strong empirical support. The premise of this model is that legitimacy and legal cynicism mediate the relationship between procedural justice and compliance behaviors. Procedural justice and legitimacy in particular have been linked to compliance and cooperation and a small, but growing body of literature has examined how these factors relate to criminal offending. There remains a number of unanswered questions surrounding the developmental processes and underlying mechanisms of procedural justice and legal socialization. The purpose of this study is twofold. First, this study will build upon recent trends in the literature to examine what factors influence changes in perceptions of procedural justice and legal socialization attitudes over time. In order to do so, the effects of a number of time-stable and time-varying covariates will be assessed. Second, this study will evaluate the effects of four possible mediating measures—legitimacy, legal cynicism, anger, and prosocial motivation—underlying the relationship between procedural justice and criminal offending. This section of the study will use a multilevel mediation method to assess whether mediation occurs between or within the individual.
Data from the Pathways to Desistance Study—a longitudinal study of 1,354 adolescents adjudicated of a serious offense followed-up for seven years—are used to address this research agenda. Results from this study offer three general conclusions. First, results show that perceptions of procedural justice are malleable, that is, they can change over time and are influenced by a number of factors. Legal socialization beliefs, however, demonstrate only marginal change over time, suggesting these beliefs to be more stable. Second, analyses indicate differing pathways and effects for direct and vicarious experiences of procedural justice. Finally, the multilevel mediation analyses reveal that within-individual changes in direct experiences of procedural justice remains a robust predictor of offending, regardless of the presence of mediating variables. Legitimacy was found to have the strongest mediation effect on between-individual differences in direct procedural justice, whereas anger partially mediated the effects of between-individual differences in vicarious procedural justice. This study concludes with a discussion of policy implications and avenues for future research.
Data from the Pathways to Desistance Study—a longitudinal study of 1,354 adolescents adjudicated of a serious offense followed-up for seven years—are used to address this research agenda. Results from this study offer three general conclusions. First, results show that perceptions of procedural justice are malleable, that is, they can change over time and are influenced by a number of factors. Legal socialization beliefs, however, demonstrate only marginal change over time, suggesting these beliefs to be more stable. Second, analyses indicate differing pathways and effects for direct and vicarious experiences of procedural justice. Finally, the multilevel mediation analyses reveal that within-individual changes in direct experiences of procedural justice remains a robust predictor of offending, regardless of the presence of mediating variables. Legitimacy was found to have the strongest mediation effect on between-individual differences in direct procedural justice, whereas anger partially mediated the effects of between-individual differences in vicarious procedural justice. This study concludes with a discussion of policy implications and avenues for future research.
ContributorsKaiser, Kimberly A (Author) / Reisig, Michael (Thesis advisor) / Sweeten, Gary (Committee member) / Wright, Kevin (Committee member) / Arizona State University (Publisher)
Created2016
Description
Statistical inference from mediation analysis applies to populations, however, researchers and clinicians may be interested in making inference to individual clients or small, localized groups of people. Person-oriented approaches focus on the differences between people, or latent groups of people, to ask how individuals differ across variables, and can help researchers avoid ecological fallacies when making inferences about individuals. Traditional variable-oriented mediation assumes the population undergoes a homogenous reaction to the mediating process. However, mediation is also described as an intra-individual process where each person passes from a predictor, through a mediator, to an outcome (Collins, Graham, & Flaherty, 1998). Configural frequency mediation is a person-oriented analysis of contingency tables that has not been well-studied or implemented since its introduction in the literature (von Eye, Mair, & Mun, 2010; von Eye, Mun, & Mair, 2009). The purpose of this study is to describe CFM and investigate its statistical properties while comparing it to traditional and casual inference mediation methods. The results of this study show that joint significance mediation tests results in better Type I error rates but limit the person-oriented interpretations of CFM. Although the estimator for logistic regression and causal mediation are different, they both perform well in terms of Type I error and power, although the causal estimator had higher bias than expected, which is discussed in the limitations section.
ContributorsSmyth, Heather Lynn (Author) / Mackinnon, David P (Thesis advisor) / Grimm, Kevin J. (Committee member) / Edwards, Michael C (Committee member) / Arizona State University (Publisher)
Created2019
Description
The purpose of this study was to investigate how to decrease teacher stress and burnout by a virtual online mindfulness practice intervention with cognitive apprenticeship, self-determination, and self-efficacy theory as the frameworks. Teaching in the United States K-12 public school system is a stressful occupation because of the higher level of responsibility within schools that requires resilient stress coping skills for overall well-being. My research project’s purpose was to examine instruction and training in mindfulness practice as a tool to cultivate stress coping skills in K-12 teachers through a six-week mindfulness virtual online course (MVOC). This study involved 5 participants with the methodology employed was an explanatory sequential mixed-methods approach which included quantitative data collection with pre-and post-surveys, which included the Perceived Stress Scale (PSS), the Kentucky Inventory of Mindfulness Skills Questionnaire (KIMS - Short), and the Philadelphia Mindfulness Scale (PHMS) with Linkert scale questions. Subsequently, followed by three qualitative interviews over six weeks to facilitate a case study consideration. The action research study results exhibited reduced stress following an increase in awareness from developing a personal mindfulness practice. Furthermore, the MVOC intervention helped the participants build a daily personalized mindfulness practice that improved their stress coping skills and was also beneficial in specific ways, which promises teachers whom routine mindfulness practice will cultivate progressively effective stress coping skills and assist K-12 teachers to enjoy increased job satisfaction and reducing the leading cause of burnout.
ContributorsPinthong, Uraipanyawan (Bo) (Author) / Giorgis, Cyndi (Thesis advisor) / Gonzales, Deborah (Committee member) / Sebren, Ann (Committee member) / Arizona State University (Publisher)
Created2021
Description
Tempe, and the greater justice system, consistently seeks to re-evaluate its operations and processes to meet the ever-increasing conflicts that are brought into the courts purview. Nationally, municipal courts have seen a decrease in civil matters, however, this is not the case in Tempe. My goal for this project was to assess and reflect on the circumstances that surround civil matters within the municipal court. As a case study, I observed and evaluated several civil court cases. In doing so, I analyzed the ways in which legal consciousness and discourse are used to solve existing civil court matters. I then took these data and considered the ways in which mediation could be used as a justice alternative. In proposing mediation as an alternative, I focus on the ways in which mediation better serves to build positive legal consciousness and address all forms of discourse that can be presented in specific civil cases. Finally, I discuss a strategy that can be used within the Tempe Courts to implement mediation as a long-term problem-solving court strategy.
ContributorsLille, Jacob (Author) / Broberg, Gregory (Thesis director) / Kane, Kevin (Committee member) / Allen, Alexis (Committee member) / School of Politics and Global Studies (Contributor) / School of International Letters and Cultures (Contributor) / School of Social Transformation (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05