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New Effect Size Rules of Thumb
Recommendations to expand Cohen’s (1988) rules of thumb for interpreting effect sizes are given to include very small, very large, and huge effect sizes. The reasons for the expansion, andExpand
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A more realistic look at the robustness and Type II error properties of the t test to departures from population normality.
The Type I and II error properties of the t test were evaluated by means of a Monte Carlo study that sampled 8 real distribution shapes identified by Micceri (1986, 1989) as being representative ofExpand
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Very large and huge effect sizes
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Implementation of Self-Determination Activities and Student Participation in IEPs
The Council for Exceptional Children conducted an online Web survey to obtain information on the instructional practices and attitudes of educators as they relate to self-determination and studentExpand
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Nonparametric Tests of Interaction in Experimental Design
Until recently the design of experiments in the behavioral and social sciences that focused on interaction effects demanded the use of the parametric analysis of variance. Yet, researchers have beenExpand
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Simulating correlated multivariate nonnormal distributions: Extending the fleishman power method
A procedure for generating multivariate nonnormal distributions is proposed. Our procedure generates average values of intercorrelations much closer to population parameters than competing proceduresExpand
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Self-Control in Postsecondary Settings
Objective: The objective of this study was to identify undergraduates’ perceptions of the impact of ADHD coaching on their academic success and broader life functioning. Method: One-on-one interviewsExpand
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Increasing physicians' awareness of the impact of statistics on research outcomes: comparative power of the t-test and and Wilcoxon Rank-Sum test in small samples applied research.
To effectively evaluate medical literature, practicing physicians and medical researchers must understand the impact of statistical tests on research outcomes. Applying inefficient statistics notExpand
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Psychometrics versus Datametrics: Comment on Vacha-Haase’s “Reliability Generalization” Method and Some Epm Editorial Policies
The present article reviews issues regarding test reliability, which is psychometric terminology, and score reliability, which is score-centric terminology. These issues have arisen, in part, due toExpand
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Review of Twenty Nonparametric Statistics and Their Large Sample Approximations.
Nonparametric procedures are often more powerful than classical tests for real world data, which are rarely normally distributed. However, there are difficulties in using these tests. ComputationalExpand
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