In this study, the authors examined the relationship between the clinical orientations of substance abuse professionals (SAPs) and their clinical decisions. Cluster analysis grouped a sample of 245 SAPs on two clinical orientations that differed in their relative endorsement of traditional versus contemporary substance abuse counseling processes…

We document a typology of perfectionism in a sample of academically talented adolescents and directly examine its relationship to indices of psychiatric symptomatology, adjustment, self-esteem, and coping. Adolescents enrolled in a state-funded residential academy for academically gifted high school students (N = 141) responded to the…

To date, finite mixtures of structural equation models (SEMMs) have been developed and applied almost exclusively for the purpose of providing model-based cluster analyses. This type of analysis constitutes a direct application of the model wherein the estimated component distributions of the latent classes are thought to represent the…

Treating Likert rating scale data as continuous outcomes in confirmatory factor analysis violates the assumption of multivariate normality. Given certain requirements pertaining to the number of categories, skewness, size of the factor loadings, and so forth, it seems nevertheless possible to recover true parameter values if the data stem from a…

The authors report outcomes for 4,777 youth served by the public mental health system in Michigan who had problems in school, at home, in interpersonal relationships, or in modulating their mood. Cluster analysis identified five subgroups: Pervasive Problems with Mood Disturbance (i.e., severe or moderate impairment in school, at home, in behavior…

In hierarchical linear models we often find that group indicator variables at the cluster level are significant predictors for the regression slopes. When this is the case, the average relationship between the outcome and a key independent variable are different from group to group. In these settings, a question such as "what range of the…

Play is the primary occupation of childhood and provides a potentially powerful means of assessing and treating children with autistic disorder. This study utilized a cross-sectional comparison design to investigate the nature of play engagement in children with AD (n = 24), relative to typically developing children (n = 34) matched for…

Hierarchical Linear Models (HLM) have been used extensively for value-added analysis, adjusting for important student and school-level covariates such as socioeconomic status. A recently proposed alternative, the Layered Mixed Effects Model (LMEM) also analyzes learning gains, but ignores sociodemographic factors. Other features of LMEM, such as…

Although often applied in practice, clinically based cognitive subtest profile analysis has failed to achieve empirical support. Nonlinear multivariate subtest profile analysis may have benefits over clinically based techniques, but the psychometric properties of these methods must be studied prior to their implementation and interpretation. The…

Discretized multivariate normal structural models are often estimated using multistage estimation procedures. The asymptotic properties of parameter estimates, standard errors, and tests of structural restrictions on thresholds and polychoric correlations are well known. It was not clear how to assess the overall discrepancy between the…

Minimization of the within-cluster sums of squares (WCSS) is one of the most important optimization criteria in cluster analysis. Although cluster analysis modules in commercial software packages typically use heuristic methods for this criterion, optimal approaches can be computationally feasible for problems of modest size. This paper presents a…

Dominance analysis (DA) is a method used to compare the relative importance of predictors in multiple regression. DA determines the dominance of one predictor over another by comparing their additional R[squared] contributions across all subset models. In this article DA is extended to multivariate models by identifying a minimal set of criteria…

The extent to which both traumatic life experiences and resiliency factors contributed to gang-involved delinquent behavior in adolescent males was investigated. Results indicated that the juvenile delinquent residential treatment setting participants had significantly higher levels of both Posttraumatic Stress Disorder (PTSD) symptomatology and…

The transition from elementary to middle school is a significant period of change for adolescents and is remarkable for several reasons, including the opportunity for new experiences and the potential for other developmental changes to occur simultaneously. Existing literature on transition includes both positive and negative outcomes for…

This dissertation is a study of factors that contribute to dropout from distance learning classes in the Kentucky Community and Technical College System (KCTCS). It is divided into five chapters. Chapter One gives a history of distance learning through in KCTCS. It includes the background of the study, statement of the problem, purpose of the…