abstract: Although the issue of factorial invariance has received increasing attention in the literature, the focus is typically on differences in factor structure across groups that are directly observed, such as those denoted by sex or ethnicity. While establishing factorial invariance across observed groups is a requisite step in making meaningful cross-group comparisons, failure to attend to possible sources of latent class heterogeneity in the form of class-based differences in factor structure has the potential to compromise conclusions with respect to observed groups and may result in misguided attempts at instrument development and theory refinement. The present studies examined the sensitivity of two widely used confirmatory factor analytic model fit indices, the chi-square test of model fit and RMSEA, to latent class differences in factor structure. Two primary questions were addressed. The first of these concerned the impact of latent class differences in factor loadings with respect to model fit in a single sample reflecting a mixture of classes. The second question concerned the impact of latent class differences in configural structure on tests of factorial invariance across observed groups. The results suggest that both indices are highly insensitive to class-based differences in factor loadings. Across sample size conditions, models with medium (0.2) sized loading differences were rejected by the chi-square test of model fit at rates just slightly higher than the nominal .05 rate of rejection that would be expected under a true null hypothesis. While rates of rejection increased somewhat when the magnitude of loading difference increased, even the largest sample size with equal class representation and the most extreme violations of loading invariance only had rejection rates of approximately 60%. RMSEA was also insensitive to class-based differences in factor loadings, with mean values across conditions suggesting a degree of fit that would generally be regarded as exceptionally good in practice. In contrast, both indices were sensitive to class-based differences in configural structure in the context of a multiple group analysis in which each observed group was a mixture of classes. However, preliminary evidence suggests that this sensitivity may contingent on the form of the cross-group model misspecification. / Dissertation/Thesis / Ph.D. Psychology 2011

No description available.

The purpose of this study was to investigate the relationship between college students' social class and their academic outcomes. A structural equation model was proposed, hypothesizing that a student's socioeconomic status (SES) is related to their motives for attending college, thus influencing their perception of fit at the university, their satisfaction with the university, their academic self-efficacy, and their grades, attendance, and likelihood for retention.. The results from a sample of 500 undergraduate students show that overall, the hypothesized model was a borderline good fit of the data. While SES was negatively related to interdependent motives for attending college, it was not related to independent motives for college. Independent motives for attending college were positively related to perceptions of fit at the university, while interdependent motives were not. Finally, fit at the university was positively related to satisfaction, which was related to intention for retention, class attendance, and academic self-efficacy. Academic self-efficacy was significantly related to students' grade point average. These results suggest that students from low SES backgrounds are more interdependent. Further, those who are more independent feel a greater sense of fit with the university and are more likely to be satisfied, express commitment to continuing at the university, and attend their classes. These results provide support for a proposition that higher education institutions should value students who have different types of motives and to consider what is communicated to students through programs and expectations that are focused on independent values.

The purpose of this grant proposal is to develop a toolkit to support school teams in the development and implementation of culturally responsive Positive Behavioral Interventions and Supports (PBIS). The toolkit is necessary to help school teams address lingering disparities in discipline and to improve school climate. Exclusionary discipline, such as out of school suspensions and expulsion, disproportionately affects ethnically and racially diverse students, and has a devastating effect on student outcomes, including academic achievement, attendance, and graduation. Ethnically and racially diverse students are also more likely to be given a disciplinary consequence for behaviors that require a subjective interpretation of the student’s behavior, which can be influenced by implicit bias. In schools that have implemented PBIS, exclusionary discipline has been shown to decrease overall, but disproportionate discipline persists. The development of a culturally responsive toolkit will support the efforts of school PBIS teams to decrease disproportionate discipline outcomes. The toolkit will assist school teams with the cultural adaptation of core features of PBIS by providing a process for addressing contextual fit of the school and soliciting feedback from the school community. The methodological approach for this project includes both qualitative and quantitative processes. An expert panel will be convened to address the complexities of implementation and cultural adaptation within the context of PBIS. The culturally responsive PBIS toolkit will consist of a comprehensive series of recommended practices, contextual considerations, evaluation tools, and resources, to be used concurrently with analysis of schoolwide data. The toolkit will be piloted in schools in the Pacific Northwest and then disseminated.

Syfte: Studien ska bidra med insikter kring hur ett externt rekryteringsföretag förhåller sig till organisationskultur och därmed den kulturella matchningen mellan organisation och kandidat.Teoretiskt perspektiv: Till grund för tolkning och analys av insamlade data ligger Schein och Scheins (2017) modell för undersökning av organisationskultur. I modellen beskrivs tre nivåer av organisationskultur: artefakter, delad tro och värderingar samt underliggande antaganden. Dessa analyseras och tolkas i sin tur utifrån tolv observerbara faktorer och uttryck av organisationskultur. Metod: En fallstudie har genomförts på ett svenskt rekryteringsföretag med hjälp av kvalitativa, semistrukturerade intervjuer. Studien har haft en iterativ ansats, där den teoretiska referensramen har utvecklats under processens gång. Empiri: I en typisk rekryteringsprocess önskar fallföretaget identifiera en matchning mellan kund och kandidat, där kundens förväntningar på kandidaten och beskrivna organisationskultur, ska överensstämma med kandidatens kompetens, erfarenhet, värderingar och egenskaper. Insamlad empiri tyder dock på att fallföretaget saknar en gemensam definition av begreppet organisationskultur och dess innehåll, varpå undersökning, tolkning och bedömning av kundens organisationskultur sker subjektivt av rekryteringskonsulter. Fallföretaget förlitar sig på kundens beskrivning av organisationskultur, utan att söka bekräftelse för dess praktiska verklighetsförankring, medan kandidatens egenskaper, värderingar etc., söks bekräftas eller dementeras genom intervjuer och referenser. Slutsats: Studien visar på att fallföretaget går miste om essentiella insikter och inte skapar en fullständig förståelse för kundens organisationskultur. I förlängningen leder detta till att de tre entiteterna inblandade i rekryteringsprocessen, kund, kandidat och konsult, inte skapar en överensstämmande, heltäckande förståelse för den praktiska verkligheten av organisationskulturen. Därmed har studien identifierat brister i den kulturella matchningen mellan organisation och individ.

abstract: Twenty-five percent of Americans are first- or second-generation immigrants (US Census, 2012). Thus, it is likely that many Americans identify with at least two cultures, that of the mainstream United States culture, and their ethnic culture from which they came, making them bicultural. However, current understanding of the impact of biculturalism on psychological functioning is quite limited in scope, as few studies have examined this association longitudinally or considered the moderating role of the cultural environment. The present study proposed to take a more comprehensive approach in understanding the consequences of biculturalism on psychological outcomes (i.e., depression, anxiety, and substance abuse symptoms) among Mexican American adolescents, as they belong to one of largest and fastest growing ethnic groups in the United States (US Census, 2013). The present study had two major goals. The first was to examine the influence of biculturalism on depression, anxiety, and substance abuse symptoms longitudinally over the course of two years. It was hypothesized that overall, biculturalism will lead to less depression, anxiety, and substance abuse symptoms. The results partially supported these predictions. For males, biculturalism was related to significantly fewer anxiety symptoms, but not for females. Further, no main effects of biculturalism were found for depression and substance abuse for males or females. The second goal of the study was to examine the potential moderating role of the cultural environment on the influence of biculturalism on mental health symptoms. It was hypothesized that bicultural individuals will exhibit less mental health symptoms in bicultural environments (person-environment fit) compared to more monocultural individuals (person-environment misfit). However, no differences are expected to ii emerge between bicultural and monocultural individuals in monocultural environments, as both groups should be well adapted in these settings. The results did not fully support these predictions. Though, biculturalism for male adolescents was related to significantly fewer anxiety symptoms in home environments where parents reported moderate degrees of biculturalism, and females' biculturalism was related to significantly fewer depression symptoms in neighborhood environments that were relatively bicultural; no effects of biculturalism were found in environments that were the most bicultural. The implications of the findings are discussed. / Dissertation/Thesis / Ph.D. Psychology 2014

Master of Science / Department of Statistics / Weixing Song / The relationship between a random variable and a random vector is often investigated through the regression modeling. Because of its relative simplicity and ease of interpretation, a particular parametric form is often assumed for the regression function. If the pre-specified function form truly reflects the truth, then the resulting estimators and inference procedures would be reliable and efficient. But if the regression function does not represent the true relationship between the response and the predictors, then the inference results might be very misleading. Therefore, lack-of-fit test should be an indispensable part in regression modeling. This report compares the finite sample performance of several classical lack-of-fit tests in regression models via simulation studies. It has three chapters. The conception of the lack-of-fit test, together with its basic setup, is briefly introduced in Chapter 1; then several classical lack-of-fit test procedures are discussed in Chapter 2; finally, thorough simulation studies are conducted in Chapter 3 to assess the finite sample performance of each procedure introduced in Chapter 2. Some conclusions are also summarized in Chapter 3. A list of MATLAB codes that are used for the simulation studies is given in the appendix.

Syfte och frågeställningar. Syftet med studien var att undersöka om 12 veckors regelbunden fysisk aktivitet, i form av kondition- och styrketräning, gav effekt på syreupptagningsförmåga hos personer med nydebuterad psykossjukdom. Frågeställningar: (1) Kan 12 veckor regelbunden kondition och styrketräning förbättra syreupptagningsförmågan hos personer med nydebuterad psykossjukdom? (2) Finns det någon skillnad mellan könen och syreupptagningsförmåga efter 12 veckors regelbunden fysisk aktivitet? Metod. Fit for life är ett forskningssamarbete mellan Karolinska Institutet, Gymnastik- och Idrottshögskolan (GIH) och Stockholms Läns Landsting vars syfte var att använda fysisk aktivitet som ett verktyg för att öka autonomi, kognitiva funktioner och kroppsfunktioner hos personer med nydebuterad psykossjukdom. Datainsamling till denna studie kom att göras utifrån Fit for life. I studien inkluderades 17 personer med nydebuterad psykossjukdom där medelvärdet för gruppens ålder var 29 ± 6,9 (år). Ett förtest utfördes följt av ett eftertest efter en träningsperiod på 12 veckor där deltagarna uppmuntrades att träna 3 gånger i veckan. Under testerna genomfördes ett submaximalt ergometercykeltest och deltagarnas maximala syreupptag uppskattades. Resultat. Bortfallet var stort, 52,7%, och det var endast två kvinnor som slutförde studien. Inga signifikanta förbättringar påträffades. En ökning i VO2max skedde hos 41,2 % av deltagarna, en minskning skedde hos 35,2%, samt hos 23,5 % var VO2max oförändrad. Av de som deltog i den organiserade träningen totalt 12 eller fler gånger ökade 57,1% sin VO2max och 42,9 % minskade sin VO2max. Gruppens medelvärde för absolut VO2max ökade med 4,1% och för det relativa VO2max med 6,3%. För de deltagare som tränade 12 gånger eller fler har medelvärdet för absolut VO2max ökat med 7,6% och för relativa VO2max med 7,8%. Dessa resultat är ej signifikanta. En av kvinnorna ökade sitt absoluta VO2max med 27,2% och det relativa VO2max med 21,8%. Den andra kvinnan ökade sitt absoluta VO2max med 8,3 % respektive det relativa med 3,7%. Hos männen ökade 33,3% sitt VO2max och 40% minskade i VO2max, samt hos 26,7% var VO2max oförändrad. Slutsats.Underlaget för denna studie var för litet och ingen slutsats kan dras då inga signifikanta förbättringar kunde ses och därmed var det inte möjligt att svara på frågeställningarna. Ett intressant fynd var däremot att när det kommer till personer med nydebuterad psykossjukdom är det viktigt att höja motivationen, stötta dem till regelbunden träning samt minska bortfallet.

Doctor of Philosophy / Department of Statistics / Weixing Song / In this dissertation, goodness-of-fit tests are proposed for checking the adequacy of parametric distributional forms of the regression error density functions and the error-prone predictor density function in measurement error models, when replications of the surrogates of the latent variables are available. In the first project, we propose goodness-of-fit tests on the density function of the regression error in the errors-in-variables model. Instead of assuming that the distribution of the measurement error is known as is done in most relevant literature, we assume that replications of the surrogates of the latent variables are available. The test statistic is based upon a weighted integrated squared distance between a nonparametric estimate and a semi-parametric estimate of the density functions of certain residuals. Under the null hypothesis, the test statistic is shown to be asymptotically normal. Consistency and local power results of the proposed test under fixed alternatives and local alternatives are also established. Finite sample performance of the proposed test is evaluated via simulation studies. A real data example is also included to demonstrate the application of the proposed test. In the second project, we propose a class of goodness-of-fit tests for checking the parametric distributional forms of the error-prone random variables in the classic additive measurement error models. We also assume that replications of the surrogates of the error-prone variables are available. The test statistic is based upon a weighted integrated squared distance between a non-parametric estimator and a semi-parametric estimator of the density functions of the averaged surrogate data. Under the null hypothesis, the minimum distance estimator of the distribution parameters and the test statistics are shown to be asymptotically normal. Consistency and local power of the proposed tests under fixed alternatives and local alternatives are also established. Finite sample performance of the proposed tests is evaluated via simulation studies.

Magister Artium (Psychology) - MA(Psych) / Globally the Subjective Well-Being (SWB) of children is recognized as having a significant effect on the child's psychological and social functioning. Furthermore, not only does children's SWB have effects on childhood well-being research, it has also increased the knowledge of how children view their life that has been determined through the measurement of specific domains that relates to children's lives. The overall aim of this study was to ascertain the SWB of children across three age groups in the Western Cape. Within this process, the study further aimed to fit the structural model depicting the nature of the relationship between global, domain specific and overall life satisfaction across three age groups. The Theory of Model Fit: Goodness of Fit and Fit Indexes was used as the theoretical position conceptualising the study. The sample included 3236 children aged 8, 10, and 12 years selected using stratified random sampling from 29 schools in the Western Cape. The study used Structural Equation Modelling and Multi-group Confirmatory Factor Analysis to address the stated aims and objectives. Ethics principles of informed consent, anonymity, the right to withdraw and privacy were adhered to within the study. Findings of this study indicate that the descriptive statistics depicted high levels of SWB for both measures with mean composite scores ranging between 81.20 to 86.15 for the SLSS; and 83.29 to 84.07 for the PWI-SC. Confirmatory factor analysis showed excellent fit for both the SLSS and the PWI-SC across age groups (multi-group model). The application of Multi-group Confirmatory Factor Analysis in the current study found the measures to be comparable across the three age groups (8, 10 & 12) for the SLSS and two age groups for the PWI-SC (10 & 12). A combined model with two latent constructs, representing different levels of abstraction was also tested. An excellent fit was obtained for this combined model. Appropriate fit statistics was obtained for the overall pooled sample. The standardised regression weights of 0.57 for the PWI-SC and 0.47 for the SLSS point to adequate loadings of the latent constructs onto the OLS. Markedly, it was found that a significant overall mean difference was found between the 10 and 12-year olds and not between the 8 and 10-year olds; while for the domain-specific PWI-SC a similar tendency was noted across the 10 and 12-year olds participants (8 year old group was not applicable in this analysis). / National Research Foundation (NRF)