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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
In the present research, elements of the intra- (i.e., family dynamics) and extra-family (i.e., characteristics of parents' occupations) contexts were examined in a longitudinal design as associated, broadly, with individuals' mental health, relationship quality, and future orientations among Mexican American families with adolescent offspring in two separate studies. The first

In the present research, elements of the intra- (i.e., family dynamics) and extra-family (i.e., characteristics of parents' occupations) contexts were examined in a longitudinal design as associated, broadly, with individuals' mental health, relationship quality, and future orientations among Mexican American families with adolescent offspring in two separate studies. The first study reviewed the utility of applying dyadic data methods to the investigation of family processes, explored the strengths three different analytic approaches (i.e., the actor-partner interdependence model, a two-intercept model, and a difference model), and applied them to the study of marital relationships (N = 246 marital dyads). Results revealed that spouses' marital negativity was related to their own somatic symptoms, whereas, spouses' somatic symptoms were associated with both their own and their partners' marital negativity, with some variations by approach. This study suggested the three analytic approaches, though designed to answer slightly different questions, yielded a similar pattern of results with several important differences. The second study utilized a person-centered approach to identify family-level patterns of both mothers' and fathers' objective occupational characteristics (i.e., self-direction, hazardous conditions, physical activity), as well as the larger sociocultural context of these patterns (N = 160 dual-earner families). Results revealed three distinct occupational contexts: Differentiated High Physical Activity, Incongruent, and Congruent High Self-Direction. Results indicated that families in the Congruent High Self-Direction profile had the highest levels of youth career aspirations, whereas, educational aspirations were the highest among youth in both the Incongruent and Congruent High Self-Direction profiles. Youth-mother and -father conflict was highest in the Congruent High Self-Direction profile, and youth-father warmth was highest for families in the Differentiated High Physical Activity profile. This study suggested that Mexican American parents work in varied occupational contexts, and these contexts were differentially associated with family relationships and youth's orientations toward the future.
ContributorsWheeler, Lorey A (Author) / Updegraff, Kimberly A (Thesis advisor) / Umana-Taylor, Adriana (Committee member) / Christopher, Scott (Committee member) / Tein, Jenn-Yun (Committee member) / Arizona State University (Publisher)
Created2012
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Description
This dissertation examines a planned missing data design in the context of mediational analysis. The study considered a scenario in which the high cost of an expensive mediator limited sample size, but in which less expensive mediators could be gathered on a larger sample size. Simulated multivariate normal data were

This dissertation examines a planned missing data design in the context of mediational analysis. The study considered a scenario in which the high cost of an expensive mediator limited sample size, but in which less expensive mediators could be gathered on a larger sample size. Simulated multivariate normal data were generated from a latent variable mediation model with three observed indicator variables, M1, M2, and M3. Planned missingness was implemented on M1 under the missing completely at random mechanism. Five analysis methods were employed: latent variable mediation model with all three mediators as indicators of a latent construct (Method 1), auxiliary variable model with M1 as the mediator and M2 and M3 as auxiliary variables (Method 2), auxiliary variable model with M1 as the mediator and M2 as a single auxiliary variable (Method 3), maximum likelihood estimation including all available data but incorporating only mediator M1 (Method 4), and listwise deletion (Method 5).

The main outcome of interest was empirical power to detect the mediated effect. The main effects of mediation effect size, sample size, and missing data rate performed as expected with power increasing for increasing mediation effect sizes, increasing sample sizes, and decreasing missing data rates. Consistent with expectations, power was the greatest for analysis methods that included all three mediators, and power decreased with analysis methods that included less information. Across all design cells relative to the complete data condition, Method 1 with 20% missingness on M1 produced only 2.06% loss in power for the mediated effect; with 50% missingness, 6.02% loss; and 80% missingess, only 11.86% loss. Method 2 exhibited 20.72% power loss at 80% missingness, even though the total amount of data utilized was the same as Method 1. Methods 3 – 5 exhibited greater power loss. Compared to an average power loss of 11.55% across all levels of missingness for Method 1, average power losses for Methods 3, 4, and 5 were 23.87%, 29.35%, and 32.40%, respectively. In conclusion, planned missingness in a multiple mediator design may permit higher quality characterization of the mediator construct at feasible cost.
ContributorsBaraldi, Amanda N (Author) / Enders, Craig K. (Thesis advisor) / Mackinnon, David P (Thesis advisor) / Aiken, Leona S. (Committee member) / Tein, Jenn-Yun (Committee member) / Arizona State University (Publisher)
Created2015
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Description
Longitudinal data from European-American (EA) and Mexican-American (MA) families (n = 179 mothers, fathers, and youth; 41% MA) was used to test a bio-psycho-cultural model of the effect of non-responsive parenting on externalizing problems in young adult offspring through the effect on the stress response system. Parenting behavior (acceptance, rejection,

Longitudinal data from European-American (EA) and Mexican-American (MA) families (n = 179 mothers, fathers, and youth; 41% MA) was used to test a bio-psycho-cultural model of the effect of non-responsive parenting on externalizing problems in young adult offspring through the effect on the stress response system. Parenting behavior (acceptance, rejection, harsh discipline) was assessed when children were in late childhood (12-13 years), cortisol samples were collected during late adolescence (18-19 years), and externalizing problems were measured in young adulthood (21-22 years). Latent profile analyses were used to examine patterns of parenting behavior in EA and MA families. A path analysis framework was used to examine how non-responsive parenting interacted with acceptance to predict adolescent stress response and subsequent externalizing problems in EA and MA young adults. Results showed different patterns of parenting behavior in EA versus MA families, with MA families demonstrating a profile of high acceptance and high non-responsiveness at higher rates than EA families. In MA families, youth adherence to the traditional cultural value of familismo related to more positive perceptions of parenting behavior. Across ethnic groups, parent rejection only predicted higher externalizing problems in young adults when acceptance was high. The effect of parent harsh discipline on offspring stress response differed by ethnicity. In MA families, harsh discipline predicted dysregulated stress response in youth when acceptance was low. In EA families, harsh discipline did not relate to youth stress response. Overall, results increase the understanding of normative and adaptive parenting behaviors in MA families. Findings inform the development of culturally-competent parenting-focused interventions that can better prevent dysregulated stress response and externalizing behavior problems in ethnically diverse youth.
ContributorsMahrer, Nicole Eva (Author) / Luecken, Linda (Thesis advisor) / Wolchik, Sharlene (Thesis advisor) / Tein, Jenn-Yun (Committee member) / Pina, Armando (Committee member) / Arizona State University (Publisher)
Created2015