Matching Items (18)

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Predicting and Promoting Healthy Diet in College-Aged Women Using the Health Action Process Approach Model

Description

One of the nation's most pressing health related issues is that of healthy diet and proper nutrition. Because much research has shown that many Americans are in poor health or

One of the nation's most pressing health related issues is that of healthy diet and proper nutrition. Because much research has shown that many Americans are in poor health or are at risk to become so due to poor diet and nutrition, understanding the psychological factors of a healthy diet or lack thereof is of the utmost importance. In order to understand the adoption and maintenance of health related behaviors, the link between intentions and behaviors must be evaluated. Of current health behavior models, the model utilized in this study was the Health Action Process Approach model (HAPA), which addressed this "intention-behavior gap." The HAPA model proposes that planning is the key mediator of the link between intentions and behavior. The current research was performed in two stages. The first stage evaluated the psychosocial constructs of the HAPA model, and their predictive utility for current diet and the second stage evaluated a planning-based intervention that aimed to increase proper nutrition in college-aged women. All HAPA constructs were found to be significantly correlated with one another, and planning was found to significantly and fully mediate the link between intention and healthy diet. The intervention did not lead to an increase in healthy diet relative to a standard-of-care control, although all participants across conditions reported increased intention, self-efficacy, and healthy diet from pre-test to follow-up.

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Date Created
  • 2013-12

Facial Expressions and Deception in the Court Room

Description

Evidence thus far has not lent credence to facilitate lie detection by the average person. According to studies, there are five major signs of lying: lip pursing, narrowed eyebrows, shoulder

Evidence thus far has not lent credence to facilitate lie detection by the average person. According to studies, there are five major signs of lying: lip pursing, narrowed eyebrows, shoulder shrugs, looking to the left, and smirking. The present study aims to determine whether training people in detecting the five signs of lying will facilitate lie detection in the average person. We analyzed the accuracy of lie detection by examining the verdicts of 155 undergraduate students during simulated police interrogations. Comparisons between the trained and untrained subjects support the hypothesis that the average person is no better than chance at detecting lies through non-verbal cues.

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Date Created
  • 2014-12

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Impact of Divorce on a Child's Perception of Parental Attachment

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With divorce rates rising (Kennedy & Ruggles, 2014), it is important to consider the impact of parental marital status on children and adolescents. In this study, we looked at whether

With divorce rates rising (Kennedy & Ruggles, 2014), it is important to consider the impact of parental marital status on children and adolescents. In this study, we looked at whether children's relationships with their parents differ based on their parents being married or divorced/separated. We hypothesized that a child's perceived relationship with their parents would be significantly influenced by parental marital status, such that those whose parents are divorced will demonstrate a negative relationship with the perception of their parents. Using data collected from the longitudinal New England Study of Suburban Youth (NESSY), we ran correlational analyses as well as an analysis of variance (ANOVA) to determine whether different aspects of attachment (Alienation, Communication, and Trust), measured with the Inventory of Parent and Peer Attachment \u2014 Revised for Children (IPPA-R) were significantly linked to parental marital status (Luthar & Barkin, 2012). Using our sample size of 489 students in the twelfth grade, we divided the groups into children with married parents (414) and children with divorced or separated parents (75). An ANOVA produced a significant difference between children's perceived relationship with their father and parental marital status; the adolescents' perception of the father's Alienation, Communication, and Trust were negatively associated with divorce. However, the child's perceived relationship with their mother was similar across both groups. These results suggest further research is needed to determine the effects of a child's perception of their relationship with their father during development, in particular in situations when parents have divorced before high school graduation.

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  • 2016-05

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Limited ""down time"" with parents: Associations with maladjustment among affluent youth

Description

Affluent children have been previously understudied and considerably neglected in developmental research due to the notion that they are "low risk." There is limited empirical research exploring the effects of

Affluent children have been previously understudied and considerably neglected in developmental research due to the notion that they are "low risk." There is limited empirical research exploring the effects of parent involvement in affluent youth: specifically, the importance of the adolescent's perception that their mother/father do not spend as much time with them as they would like. The goals of the study were to explore the role of this dimension of perceived parental involvement in anxious-depressed symptoms, somatic symptoms, rule breaking behaviors and substance use with upper-class suburban youth. The sample was taken from the New England Study of Suburban Youth Cohort (NESSY) (Luthar & Latendresse, 2005b) consisting of 252 high school students in the 12th grade located in an affluent community in the Northeast. Results showed that the participants who indicated their fathers could have dinner with them more often if they tried presented significant group differences in anxious-depressed symptoms, somatic symptoms, and rule breaking behaviors while substance use trended towards significant. Thus, these data demonstrate that parent-child relationships are not only important for infant and child development, but are also an integral part of development of adaptive behaviors during adolescence. In addition, the data suggest the benefits from having strong, supportive, and stable relationships with not only mothers but with fathers as well. Results from post hoc analyses revealed perceived absence of fathers at dinnertime affects the adolescent more than the perceived absence of mothers at dinnertime. Finally, teens who indicated a need to spend more dinnertimes with their father may be suffering from a lack of open communication and opportunities to discuss social and emotional issues that are conducive to adolescent development and adjustment.

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Date Created
  • 2016-12

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Testing the limits of latent class analysis

Description

The purpose of this study was to examine under which conditions "good" data characteristics can compensate for "poor" characteristics in Latent Class Analysis (LCA), as well as to set forth

The purpose of this study was to examine under which conditions "good" data characteristics can compensate for "poor" characteristics in Latent Class Analysis (LCA), as well as to set forth guidelines regarding the minimum sample size and ideal number and quality of indicators. In particular, we studied to which extent including a larger number of high quality indicators can compensate for a small sample size in LCA. The results suggest that in general, larger sample size, more indicators, higher quality of indicators, and a larger covariate effect correspond to more converged and proper replications, as well as fewer boundary estimates and less parameter bias. Based on the results, it is not recommended to use LCA with sample sizes lower than N = 100, and to use many high quality indicators and at least one strong covariate when using sample sizes less than N = 500.

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Created

Date Created
  • 2012

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Estimating causal direct and indirect effects in the presence of post-treatment confounders: a simulation study

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

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.

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Date Created
  • 2013

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The roles of sensation seeking and level of response to negative, sedative alcohol effects in the intergenerational transmission of risk for developing alcohol use disorders

Description

The present study tested the respective mediating effects of sensation seeking and initial level of response (LR) to negative, sedative alcohol effects on the relation between the density of familial

The present study tested the respective mediating effects of sensation seeking and initial level of response (LR) to negative, sedative alcohol effects on the relation between the density of familial history of alcoholism and adolescent alcohol use. Additionally, the present study tested the direct effect of LR to negative, sedative alcohol effects on adolescent drinking over and above the effects of sensation seeking; and also tested the moderating effect of sensation seeking on the relation between level of response negative, sedative alcohol effects and adolescent drinking. Specifically, OLS regression models first estimated the effects of sensation seeking, LR to negative, sedative alcohol effects, and their interaction on alcohol outcomes, over and above the influence of covariates. Indirect effects were then tested using the PRODCLIN method through RMediation. Analyses failed to support sensation seeking as a mediator in the relation between familial history of alcoholism and adolescent drinking, and as a moderator of the relation between LR and adolescent drinking. However, analyses did support a robust direct effect of LR to negative, sedative alcohol effects on adolescent alcohol involvement. A significant mediating effect of initial LR to negative, sedative alcohol effects on the relation between familial alcoholism and adolescent drinking was found, however failed to maintain significance in post-hoc analyses attenuating the downward bias of the measure of initial LR. Initial LR to negative, sedative alcohol effects continued to predict adolescent drinking after attenuating measure bias. These findings strengthen research on initial LR to negative, sedative alcohol effects as a risk for greater alcohol involvement in adolescence, and underscore the complexity of studying the familial transmission of alcoholism in adolescent populations

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Created

Date Created
  • 2015

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Dynamic assessment of narratives among Navajo Head Start children

Description

Purpose: Over-identification of Navajo Head Start children into special education on the Navajo Reservation has come to the attention of Tribal leaders, Educational leaders, and parents due to the use

Purpose: Over-identification of Navajo Head Start children into special education on the Navajo Reservation has come to the attention of Tribal leaders, Educational leaders, and parents due to the use of invalid assessment measures. Dynamic assessment (DA) of narratives may be a tool for distinguishing language differences from language disorders. The purpose of this study is to determine whether the Predictive Early Assessment of Reading and Language (PEARL), a dynamic assessment of narratives, accurately classifies Navajo Head Start students with typically developing (TD) language or with language impairment (LI), and to examine which measures best predict children’s overall performances on the PEARL.

Method: Ninety, 4- and 5-year-old Navajo preschoolers with LI and with TD language were selected. Children completed the PEARL, which measured both language comprehension and production using pretest and posttest scores, and a modifiability scale. In addition, children completed the Clinical Evaluation of Language Fundamental, Preschool, Second Edition (CELF – Preschool 2) and language samples. A Navajo Speech Language Pathologist confirmed the diagnosis of the participants. Research assistants pretested, briefly taught the principles of narrative structure (story grammar, language complexity and episode) and evaluated response to learning using an index of modifiability.

Results: Results of discriminant analysis indicated that PEARL pretest differentiated both ability groups with 89% accuracy. In addition, posttest scores discriminated with 89% accuracy and modifiability scores with 100% accuracy. Further, the subtest story grammar was the best predictor at pretest and posttest, although modifiability scores were better predictors of both ability groups.

Conclusion: Findings indicate that the PEARL is a promising assessment for accurately differentiating Navajo preschool children with LI from Navajo preschool children with TD language. The PEARL’s recommended pretest cut score over-identified Navajo children with TD language; therefore, a new recommended cut score was determined.

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Date Created
  • 2017

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Peer reputation among affluent middle school youth: ramifications for maladjustment versus competence by age 18

Description

Given the major investment young people make in earning and maintaining a peer reputation, our goal in this study was to explore the association between dimensions of negative and positive

Given the major investment young people make in earning and maintaining a peer reputation, our goal in this study was to explore the association between dimensions of negative and positive peer reputation in middle school and adjustment several years later, by the end of high school, among upper middle class youth. Prior research has shown negative reputations such as aggressive-disruptive and sensitive-isolated to be associated with maladjustment later in life, whereas reputations like popular and prosocial-leader have been related to positive future outcomes. However, there are contrary findings that reveal a more complex relationship between peer reputation and adjustment, showing certain “negative” reputations to be tied with better outcomes in some domains and the converse in others. Using a sample of middle school students, a confirmatory factor analysis (CFA) was performed to test a four-factor model of the Revised Class Play, a peer report measure on peer reputations. CFA findings supported the four-factor model with the following reputations: popular, prosocial, aggressive, and isolated. Structural equation models were used to predict 12th grade adjustment outcomes (academic achievement, psychopathology, substance use) from middle school peer reputation. Prosocial reputation in middle school was connected to higher academic achievement and fewer externalizing symptoms in 12th grade. Both prosocial and isolated peer reputation were negatively associated with alcohol, cigarette, and marijuana use, whereas a popular reputation was related to higher levels of alcohol use. Middle school reputation did not predict internalizing symptoms in 12th grade. Findings are discussed in terms of adaptive and maladaptive adjustment outcomes associated with each peer reputation and implications for future research.

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Date Created
  • 2016

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Handling sparse and missing data in functional data analysis: a functional mixed-effects model approach

Description

This paper investigates a relatively new analysis method for longitudinal data in the framework of functional data analysis. This approach treats longitudinal data as so-called sparse functional data. The first

This paper investigates a relatively new analysis method for longitudinal data in the framework of functional data analysis. This approach treats longitudinal data as so-called sparse functional data. The first section of the paper introduces functional data and the general ideas of functional data analysis. The second section discusses the analysis of longitudinal data in the context of functional data analysis, while considering the unique characteristics of longitudinal data such, in particular sparseness and missing data. The third section introduces functional mixed-effects models that can handle these unique characteristics of sparseness and missingness. The next section discusses a preliminary simulation study conducted to examine the performance of a functional mixed-effects model under various conditions. An extended simulation study was carried out to evaluate the estimation accuracy of a functional mixed-effects model. Specifically, the accuracy of the estimated trajectories was examined under various conditions including different types of missing data and varying levels of sparseness.

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Created

Date Created
  • 2016