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- Creators: Chopin, Frédéric, 1810-1849
Description
Including a covariate can increase power to detect an effect between two variables. Although previous research has studied power in mediation models, the extent to which the inclusion of a mediator will increase the power to detect a relation between two variables has not been investigated. The first study identified situations where empirical and analytical power of two tests of significance for a single mediator model was greater than power of a bivariate significance test. Results from the first study indicated that including a mediator increased statistical power in small samples with large effects and in large samples with small effects. Next, a study was conducted to assess when power was greater for a significance test for a two mediator model as compared with power of a bivariate significance test. Results indicated that including two mediators increased power in small samples when both specific mediated effects were large and in large samples when both specific mediated effects were small. Implications of the results and directions for future research are then discussed.
ContributorsO'Rourke, Holly Patricia (Author) / Mackinnon, David P (Thesis advisor) / Enders, Craig K. (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2013
Description
Possible selves researchers have uncovered many issues associated with the current possible selves measures. For instance, one of the most famous possible selves measures, Oyserman (2004)'s open-ended possible selves, has proven to be difficult to score reliably and also involves laborious scoring procedures. Therefore, this study was initiated to develop a close-ended measure, called the Persistent Academic Possible Selves Scale for Adolescents (PAPSS), that meets these challenges. The PAPSS integrates possible selves theories (personal and social identities) and educational psychology (self-regulation in social cognitive theory). Four hundred and ninety five junior high and high school students participated in the validation study of the PAPSS. I conducted confirmatory factor analyses (CFA) to compare fit for a baseline model to the hypothesized models using Mplus version 7 (Muthén & Muthén, 2012). A weighted least square means and a variance adjusted (WLSMV) estimation method was used for handling multivariate nonnormality of ordered categorical data. The final PAPSS has validity evidence based on the internal structure. The factor structure is composed of three goal-driven factors, one self-regulated factor that focuses on peers, and four self-regulated factors that emphasize the self. Oyserman (2004)'s open-ended questionnaire was used for exploring the evidence of convergent validity. Many issues regarding Oyserman (2003)'s instructions were found during the coding process of academic plausibility. It was complicated to detect hidden academic possible selves and strategies from non-academic possible selves and strategies. Also, interpersonal related strategies were over weighted in the scoring process compared to interpersonal related academic possible selves. The study results uncovered that all of the academic goal-related factors in the PAPSS are significantly related to academic plausibility in a positive direction. However, self-regulated factors in the PAPSS are not. The correlation results between the self-regulated factors and academic plausibility do not provide the evidence of convergent validity. Theoretical and methodological explanations for the test results are discussed.
ContributorsLee, Ji Eun (Author) / Husman, Jenefer (Thesis advisor) / Green, Samuel (Committee member) / Millsap, Roger (Committee member) / Brem, Sarah (Committee member) / Arizona State University (Publisher)
Created2013
Description
Type 1 Diabetes Mellitus (T1DM) is a chronic disease that requires maintaining tight metabolic control through complex behavioral and pharmaceutical regimens. Subtle cognitive impairments and stress response dysregulation may partially account for problems negotiating life changes and maintaining treatment adherence among emerging adults. The current study examined whether young adults with T1DM physiologically respond to psychological stress in a dysregulated manner compared to non-diabetic peers, and if such individuals also demonstrated greater cognitive declines following psychological stress. Participants included 23 young adults with T1DM and 52 non-diabetic controls yoked to T1DM participants based on age, gender, ethnicity, participant education, and maternal education. Participants completed a laboratory-based social stressor, pre- and post-stressor neurocognitive testing, provided fingerstick blood spots (for glucose levels) and salivary samples (for cortisol levels) at five points across the protocol, and completed psychosocial questionnaires. Related measures ANOVAs were conducted to assess differences between T1DM participants and the average of yoked controls on cortisol and cognitive outcomes. Results demonstrated that differences in cortisol reactivity were dependent on T1DM participants' use of insulin pump therapy (IPT). T1DM participants not using IPT demonstrated elevated cortisol reactivity compared to matched controls. There was no difference in cortisol reactivity between the T1DM participants on IPT and matched controls. On the Stroop task, performance patterns did not differ between participants with T1DM not on IPT and matched controls. The performance of participants with T1DM on IPT slightly improved following the stressor and matched controls slightly worsened. On the Trail Making Test, the performance of participants with T1DM was not different following the stressor whereas participants without T1DM demonstrated a decline following the stressor. Participants with and without T1DM did not differ in patterns of performance on the Rey Verbal Learning Task, Sustained Attention Allocation Task, Controlled Oral Word Association Task, or overall cortisol output across participation. The results of this study are suggestive of an exaggerated cortisol response to psychological stress in T1DM and indicate potential direct and indirect protective influences of IPT.
ContributorsMarreiro, Catherine (Author) / Luecken, Linda (Thesis advisor) / Doane, Leah (Thesis advisor) / Barrera, Manuel (Committee member) / Aiken, Leona (Committee member) / Arizona State University (Publisher)
Created2013
Description
The purpose of this dissertation was to develop a Compassionate Communication Scale (CCS) by conducting a series of studies. The first study used qualitative data to identify and develop initial scale items. A series of follow-up studies used exploratory factor analysis to investigate the underlying structure of the CCS. A three-factor structure emerged, which included: Compassionate conversation, such as listening, letting the distressed person disclose feelings, and making empathetic remarks; compassionate touch, such as holding someone's hand or patting someone's back; and compassionate messaging, such as posting an encouraging message on a social networking site or sending a sympathetic email. The next study tested convergent and divergent validity by determining how the three forms of compassionate communication associate with various traits. Compassionate conversation was positively related to compassion, empathetic concern, perspective taking, emotional intelligence, social expressivity, emotional expressivity and benevolence, and negatively related to verbal aggressiveness and narcissism. Compassionate touch was positively correlated with compassion, empathetic concern, perspective taking, emotional intelligence, social expressivity, emotional expressivity, and benevolence, and uncorrelated with verbal aggressiveness and benevolence. Finally, compassionate messaging was positively correlated with social expressivity, emotional expressivity, and uncorrelated with verbal aggressiveness and narcissism. The next study focused on cross-validation and criterion-related validity. Correlations showing that self-reports of a person's compassionate communication were positively related to a friend or romantic partner's report of that person's compassionate communication provided cross-validation. The test for criterion-related validity examined whether compassionate communication predicts relational satisfaction. Regression analyses revealed that people were more relationally satisfied when they perceived themselves to use compassionate conversation, when they perceived their partner to use compassionate conversation, and when their partner reported using compassionate conversation. This finding did not extend to compassionate touch or compassionate messaging. In fact, in one regression analysis, people reported more relational satisfaction when they perceived that their partners used high levels of compassionate conversation and low levels of compassionate touch. Overall, the analyses suggest that of the three forms of compassionate communication, compassionate conversation is most strongly related to relational satisfaction. Taken together, this series of studies provides initial evidence for the validity of the CCS.
ContributorsRamos Salazar, Leslie (Author) / Guerrero, Laura (Thesis advisor) / Roberto, Anthony (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2013
Description
Despite the compelling nature of goodness of fit and widespread recognition of the concept, empirical support has lagged, potentially due to complexities inherent in measuring such a complicated, relational construct. The present study examined two approaches to measuring goodness of fit in mother-child dyads and prospectively explored associations to mother-child relationship quality, child behavior problems, and parenting stress across the preschool period. In addition, as goodness of fit might be particularly important for children with developmental delays, child developmental risk status was considered as a moderator of goodness of fit processes. Children with (n = 110) and without (n = 137) developmental delays and their mothers were coded while interacting during a number of lab tasks at child age 36 months and during naturalistic home observations at child age 48 months. Mothers and father completed questionnaires at child ages 36 and 60 months assessing child temperamental characteristics, child behavior problems, and parenting stress. Results highlight child-directed effects on mother-child goodness of fit processes across the early child developmental period. Although there was some evidence that mother-child goodness of fit was associated with parenting stress 2 years later, goodness of fit remains an elusive concept. More precise models and expanded developmental perspectives are needed in order to fully capture the transactional and dynamic nature of goodness of fit in the parent-child relationship.
ContributorsNewland, Rebecca Pauline (Author) / Crnic, Keith (Thesis advisor) / Bradley, Robert (Committee member) / Jahromi, Laudan (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2014
Description
Methods to test hypotheses of mediated effects in the pretest-posttest control group design are understudied in the behavioral sciences (MacKinnon, 2008). Because many studies aim to answer questions about mediating processes in the pretest-posttest control group design, there is a need to determine which model is most appropriate to test hypotheses about mediating processes and what happens to estimates of the mediated effect when model assumptions are violated in this design. The goal of this project was to outline estimator characteristics of four longitudinal mediation models and the cross-sectional mediation model. Models were compared on type 1 error rates, statistical power, accuracy of confidence interval coverage, and bias of parameter estimates. Four traditional longitudinal models and the cross-sectional model were assessed. The four longitudinal models were analysis of covariance (ANCOVA) using pretest scores as a covariate, path analysis, difference scores, and residualized change scores. A Monte Carlo simulation study was conducted to evaluate the different models across a wide range of sample sizes and effect sizes. All models performed well in terms of type 1 error rates and the ANCOVA and path analysis models performed best in terms of bias and empirical power. The difference score, residualized change score, and cross-sectional models all performed well given certain conditions held about the pretest measures. These conditions and future directions are discussed.
ContributorsValente, Matthew John (Author) / MacKinnon, David (Thesis advisor) / West, Stephen (Committee member) / Aiken, Leona (Committee member) / Enders, Craig (Committee member) / Arizona State University (Publisher)
Created2015
Description
Organized activity participation is associated with a wide array of positive developmental outcomes. Latinos are one of the largest and fastest growing ethnic groups in the U.S., yet are less likely to participate in organized activities than their peers. Theoretically, the alignment or fit between adolescents' and their activities' characteristics is critical to support youths' use and engagement in organized activities. Using qualitative data in Study 1, I examined parents' and adolescents' perspectives and experiences related to several indicators of ethnicity and culture in their activities. Results suggested that alignment on Spanish-language use was critical for participation. However, some Latino families did not prefer aspects of ethnicity and culture in their activities because adolescents learned about their culture with family or because adolescents wanted to fit in with their majority White peers. Study 2 tested quantitatively whether features of ethnicity and culture in the activity mattered for Latino adolescents' experiences during activities. Ethnic and cultural features in activities, particularly respect for one's ethnicity and culture, fostered positive experiences during activities. Unexpectedly, some ethnic and cultural features were detrimental, such that overt teaching about ethnicity and culture was related to negative feelings during the activity. There was little evidence that the relation between ethnic and cultural features in activities and concurrent experiences varied by Latino cultural orientation. Integrating the findings across these two studies, there was mixed evidence for the traditional theoretical notions that optimal development occurs in environments that fit with individual's characteristics. Complementary fit was optimal when adolescents' needs were considered across the many contexts in which their lives are embedded, including their families and neighborhoods. I recommend that practitioners should take care in learning about the specific families and youth that their activity serves to best understand how to meet their needs. Some aspects of culture, such as Spanish-language use may be critical for participation; other aspects may require special attention from activity leaders, such as teaching about ethnicity and culture. This dissertation is an important step in understanding how to best design activities that promote the recruitment and retention of Latino youth in organized activities.
ContributorsVest, Andrea Elaine (Author) / Simpkins, Sandra D (Thesis advisor) / Menjivar, Cecilia (Committee member) / Umaña-Taylor, Adriana J. (Committee member) / Updegraff, Kimberly A. (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2014
Description
Missing data are common in psychology research and can lead to bias and reduced power if not properly handled. Multiple imputation is a state-of-the-art missing data method recommended by methodologists. Multiple imputation methods can generally be divided into two broad categories: joint model (JM) imputation and fully conditional specification (FCS) imputation. JM draws missing values simultaneously for all incomplete variables using a multivariate distribution (e.g., multivariate normal). FCS, on the other hand, imputes variables one at a time, drawing missing values from a series of univariate distributions. In the single-level context, these two approaches have been shown to be equivalent with multivariate normal data. However, less is known about the similarities and differences of these two approaches with multilevel data, and the methodological literature provides no insight into the situations under which the approaches would produce identical results. This document examined five multilevel multiple imputation approaches (three JM methods and two FCS methods) that have been proposed in the literature. An analytic section shows that only two of the methods (one JM method and one FCS method) used imputation models equivalent to a two-level joint population model that contained random intercepts and different associations across levels. The other three methods employed imputation models that differed from the population model primarily in their ability to preserve distinct level-1 and level-2 covariances. I verified the analytic work with computer simulations, and the simulation results also showed that imputation models that failed to preserve level-specific covariances produced biased estimates. The studies also highlighted conditions that exacerbated the amount of bias produced (e.g., bias was greater for conditions with small cluster sizes). The analytic work and simulations lead to a number of practical recommendations for researchers.
ContributorsMistler, Stephen (Author) / Enders, Craig K. (Thesis advisor) / Aiken, Leona (Committee member) / Levy, Roy (Committee member) / West, Stephen G. (Committee member) / Arizona State University (Publisher)
Created2015
Description
The effects of preventive interventions are found to be related to participants' responsiveness to the program, or the degree to which participants attend sessions, engage in the material, and use the program skills. The current study proposes a multi-dimensional method for measuring responsiveness to the Family Bereavement Program (FBP), a parenting-focused program to prevent mental health problems for children who experienced the death of a parent. It examines the relations between individual-level risk-factors and responsiveness to the program, as well as the relations between responsiveness and program outcomes. The sample consists of 90 caregivers and 135 children assigned to the intervention condition of an efficacy trial of the FBP. Caregivers' responsiveness to the 12-week program was measured using a number of indicators, including attendance, completion of weekly "homework" assignments, overall program skill use, perceived helpfulness of the program and program skills, and perceived group environment. Three underlying dimensions of responsiveness were identified: Skill Use, Program Liking, and Perceived Group Environment. Positive parenting and child externalizing problems at baseline were found to predict caregiver Skill Use. Skill Use and Perceived Group Environment predicted changes in caregiver grief and reports of child behavior problems at posttest and 11-month follow-up. Caregivers with better Skill Use had better positive parenting outcomes. Skill use mediated the relation between baseline positive parenting and improvements in positive parenting at 11-month follow-up.
ContributorsSchoenfelder, Erin (Author) / Sandler, Irwin N. (Thesis advisor) / Wolchik, Sharlene (Committee member) / Millsap, Roger (Committee member) / Barrera, Manuel (Committee member) / Arizona State University (Publisher)
Created2012
Description
The purpose of this study was to investigate the effect of complex structure on dimensionality assessment in compensatory and noncompensatory multidimensional item response models (MIRT) of assessment data using dimensionality assessment procedures based on conditional covariances (i.e., DETECT) and a factor analytical approach (i.e., NOHARM). The DETECT-based methods typically outperformed the NOHARM-based methods in both two- (2D) and three-dimensional (3D) compensatory MIRT conditions. The DETECT-based methods yielded high proportion correct, especially when correlations were .60 or smaller, data exhibited 30% or less complexity, and larger sample size. As the complexity increased and the sample size decreased, the performance typically diminished. As the complexity increased, it also became more difficult to label the resulting sets of items from DETECT in terms of the dimensions. DETECT was consistent in classification of simple items, but less consistent in classification of complex items. Out of the three NOHARM-based methods, χ2G/D and ALR generally outperformed RMSR. χ2G/D was more accurate when N = 500 and complexity levels were 30% or lower. As the number of items increased, ALR performance improved at correlation of .60 and 30% or less complexity. When the data followed a noncompensatory MIRT model, the NOHARM-based methods, specifically χ2G/D and ALR, were the most accurate of all five methods. The marginal proportions for labeling sets of items as dimension-like were typically low, suggesting that the methods generally failed to label two (three) sets of items as dimension-like in 2D (3D) noncompensatory situations. The DETECT-based methods were more consistent in classifying simple items across complexity levels, sample sizes, and correlations. However, as complexity and correlation levels increased the classification rates for all methods decreased. In most conditions, the DETECT-based methods classified complex items equally or more consistent than the NOHARM-based methods. In particular, as complexity, the number of items, and the true dimensionality increased, the DETECT-based methods were notably more consistent than any NOHARM-based method. Despite DETECT's consistency, when data follow a noncompensatory MIRT model, the NOHARM-based method should be preferred over the DETECT-based methods to assess dimensionality due to poor performance of DETECT in identifying the true dimensionality.
ContributorsSvetina, Dubravka (Author) / Levy, Roy (Thesis advisor) / Gorin, Joanna S. (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2011