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Random Forests is a statistical learning method which has been proposed for propensity score estimation models that involve complex interactions, nonlinear relationships, or both of the covariates. In this dissertation I conducted a simulation study to examine the effects of three Random Forests model specifications in propensity score analysis. The

Random Forests is a statistical learning method which has been proposed for propensity score estimation models that involve complex interactions, nonlinear relationships, or both of the covariates. In this dissertation I conducted a simulation study to examine the effects of three Random Forests model specifications in propensity score analysis. The results suggested that, depending on the nature of data, optimal specification of (1) decision rules to select the covariate and its split value in a Classification Tree, (2) the number of covariates randomly sampled for selection, and (3) methods of estimating Random Forests propensity scores could potentially produce an unbiased average treatment effect estimate after propensity scores weighting by the odds adjustment. Compared to the logistic regression estimation model using the true propensity score model, Random Forests had an additional advantage in producing unbiased estimated standard error and correct statistical inference of the average treatment effect. The relationship between the balance on the covariates' means and the bias of average treatment effect estimate was examined both within and between conditions of the simulation. Within conditions, across repeated samples there was no noticeable correlation between the covariates' mean differences and the magnitude of bias of average treatment effect estimate for the covariates that were imbalanced before adjustment. Between conditions, small mean differences of covariates after propensity score adjustment were not sensitive enough to identify the optimal Random Forests model specification for propensity score analysis.
ContributorsCham, Hei Ning (Author) / Tein, Jenn-Yun (Thesis advisor) / Enders, Stephen G (Thesis advisor) / Enders, Craig K. (Committee member) / Mackinnon, David P (Committee member) / Arizona State University (Publisher)
Created2013
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Description
It is well-established that maternal depression is significantly related to internalizing and externalizing behavioral problems and psychopathology in general. However, research suggests maternal depression does not account for all the variance of these outcomes and that other family contextual factors should be investigated. The role of fathers beyond their simple

It is well-established that maternal depression is significantly related to internalizing and externalizing behavioral problems and psychopathology in general. However, research suggests maternal depression does not account for all the variance of these outcomes and that other family contextual factors should be investigated. The role of fathers beyond their simple presence or absence is one factor that needs to be further investigated in the context of maternal depression. The proposed study used prospective and cross-sectional analyses to examine father effects (i.e., paternal depression, alcohol use, involvement, and familism) on youth internalizing and externalizing symptoms within the context of maternal depression. The sample consisted of 405 Mexican-American families who had a student in middle school. Data were collected when the students were in 7th and 10th grade. Results from path analyses revealed that maternal depression significantly predicted concurrent youth internalizing symptoms in 7th and 10th grade and externalizing symptoms in 10th grade. In contrast, paternal depression was not related to adolescent symptomatology at either time point, nor was paternal alcoholism, and analyses failed to support moderating effects for any of the paternal variables. However, paternal involvement (father-report) uniquely predicted youth internalizing and externalizing symptoms over and above maternal depression in 7th grade. Youth report of paternal involvement uniquely predicted both internalizing and externalizing in 7th and 10th grade. Paternal familism uniquely predicted youth externalizing symptoms in 7th grade. The present findings support that maternal depression, but not paternal depression, is associated with concurrent levels of youth symptomatology in adolescence. The study did not support that fathers adjustment moderated (exacerbate or buffer) maternal depression effects. However, paternal involvement and paternal familism showed compensatory effects on youth symptomatology in concurrent analyses.
ContributorsMontano, Zorash (Author) / Gonzales, Nancy A. (Thesis advisor) / Tein, Jenn-Yun (Committee member) / Roosa, Mark (Committee member) / Arizona State University (Publisher)
Created2013
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Description
Internalizing symptoms are prevalent among adolescents, especially among Latinos, and can have negative consequences on health and development. Understanding the risk and protective factors leading to internalizing difficulties among Latino youth is critical. The current study sought to assess the effects of family risk and peer social rejection in the

Internalizing symptoms are prevalent among adolescents, especially among Latinos, and can have negative consequences on health and development. Understanding the risk and protective factors leading to internalizing difficulties among Latino youth is critical. The current study sought to assess the effects of family risk and peer social rejection in the seventh grade on internalizing symptoms in the tenth grade, and the potential buffering effects of social support from family and from friends, among a sample of 749 Mexican American youth. Structural equation modeling was used to examine pathways from seventh grade family risk and peer social rejection to internalizing symptoms in the tenth grade. Perceived social support from family and perceived social support from friends were tested as moderators of these relations. Gender differences in these pathways were also assessed. Results showed that family risk did not predict tenth grade internalizing symptoms, but that peer social rejection predicted increased internalizing symptoms for girls. Furthermore, buffering effects were not confirmed; rather social support from both friends and family had no effect on the relation between family risk and internalizing symptoms, and high levels of social support from both sources amplified the effect of peer social rejection on internalizing symptoms. Secondary analyses suggested that at low levels of social support from both sources, peer social rejection predicted decreased internalizing symptoms for males. Limitations and implications for prevention and future research are discussed.
ContributorsJenchura, Emily C (Author) / Gonzales, Nancy (Thesis advisor) / Tein, Jenn-Yun (Committee member) / Luecken, Linda (Committee member) / Arizona State University (Publisher)
Created2015