A Note on the Assumption of Identical Distributions for Nonparametric Tests of Location

Often, when testing for shift in location, researchers will utilize nonparametric statistical tests in place of their parametric counterparts when there is evidence or belief that the assumptions of the parametric test are not met (i.e., normally distributed dependent variables). An underlying and often unattended to assumption of nonparametric tests of location is that of identical distributions. The assumption of identical distributions requires that distributions conform to one another in terms of variability and shape (i.e., variance, skew and kurtosis). The purpose of the current study is to demonstrate, via the use of Monte Carlo simulation, the assumption of identical distribution using the Wilcoxon-Mann-Whitney (WMW) test and the Student t-test for comparison. For each of the conditions, there are several levels of sample size, variance ratio, group sample size ratio, and degree of skew in the parent distribution. Empirical Type I error rates are compared to nominal Type I error rates to determine the validity of the result for each run of the simulation. Violation of the assumption of identical distributions lead to bias in the result of the WMW test and the Student t-test. Practical implications are also discussed. Accessed 1,139 times on https://pareonline.net from April 05, 2018 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Examining the Effectiveness of an Orthographic-Based Intervention for Children with Reading Disabilities

It has been well-documented that combined phonological awareness and word-identification training provide the most effective way of strengthening reading ability in children with Reading Disabilities (RDs). With that said, these findings are based on the assumption that all children with RDs represent a homogenous population and react similarly to specific intervention approaches. Recognizing the heterogeneity within the RD population, preliminary research has surfaced which challenges the combined approach in favor of techniques which address the relative deficit in either phonological or word-discrimination (orthographic) processes. Continuing in this line of research, a study was conducted to examine the effectiveness of an orthographic-based intervention design to improve reading ability for children with orthographic skill deficits. The study took place at a private, not-for-profit, school designed for children with a variety of Learning Disabilities. Through utilizing a single-case multiple-baseline research design, 12 children with RDs in grades 3 through 6 (3 students per grade) were matched on reading ability and intelligence prior to beginning the intervention. The results of this study will be discussed in relation to the importance of assessing and intervening for specific reading difficulties within RD populations

Art Making Promotes Mental Health: A Solution for Schools That Time Forgot

This article presents art as a tool for promoting mental health in schools by examining the effects of art making in a sample of 104 school-based mental health professionals. It unites findings from unrelated disciplines to derive and test a new conceptual framework proposing that active engagement in a visual-tactile process over time mediates a shift to healthy mental states and that regular engagement in such process builds mental health capacity. Four hypotheses are tested through psychometrics with statistically significant findings for all (p < .05). Through this study, we advance Flow Theory in identifying a new causal mechanism for accessing Flow; and we make a novel, interdisciplinary contribution to the field of mental health in providing psychometric evidence that making visual art promotes mental health.Cet article présente l’art comme un outil pour promouvoir la santé mentale dans les écoles. Il examine les effets de la création artistique auprès de 104 professionnels de la santé mentale en milieu scolaire. Il réunit les résultats de diverses disciplines afin de dégager et de tester un nouveau cadre conceptuel proposant que l’engagement actif dans un processus visuel tactile au fil du temps facilite une bonne santé mentale, et qu’un engagement constant dans un tel processus renforce la capacité de santé mentale. Quatre hypothèses sont testées au moyen de mesures psychométriques, et elles obtiennent toutes des résultats statistiquement significatifs (p < .05). Grâce à cette étude, nous faisons progresser la théorie du flux (Flow Theory) en identifiant un nouveau mécanisme causal pour accéder à ce flux ; et nous apportons une contribution novatrice et interdisciplinaire au domaine de la santé mentale en fournissant des preuves psychométriques que les arts visuels favorisent la santé mentale