Increasing the correlation between the independent variable and the mediator ("a" coefficient) increases the effect size ("ab") for mediation analysis; however, increasing a by definition increases collinearity in mediation models. As a result, the standard error of product tests increase. The variance inflation caused by…

For intervention studies involving binary treatment variables, procedures for power analysis have been worked out and computerized estimation tools are generally available. The purpose of this study is to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval,…

Proper management of logistical issues in Teacher education programme tends to promote the quality of preparation of school teachers. The main objective of the study was to investigate challenges of administering teacher education programmes in Kenyan universities. The theoretical framework of the study was adopted as used by Koehler and Mishra's…

Emotional intelligence is the capability to realize, to create, to comprehend emotions and sentimental knowledge, and to reflectively control emotions and to improve emotional and mental growth. The purpose of this study is to examine the relationship between EFL teachers' commitment to professional ethics and their emotional intelligence. To…

Evaluators of education interventions are increasingly designing studies to detect impacts much smaller than the 0.20 standard deviations that Cohen (1988) characterized as "small." While the need to detect smaller impacts is based on compelling arguments that such impacts are substantively meaningful, the drive to detect smaller impacts…

Researchers occasionally have to work with an extremely small sample size, defined herein as "N" less than or equal to 5. Some methodologists have cautioned against using the "t"-test when the sample size is extremely small, whereas others have suggested that using the "t"-test is feasible in such a case. The present…

The uses and methodology of factor analysis are widely debated and discussed, especially the issues of rotational use, methods of confirmatory factor analysis, and adequate sample size. The variety of perspectives and often conflicting opinions can lead to confusion among researchers about best practices for using factor analysis. The focus of the…

The authors generated exact probability distributions for sample sizes up to 35 in each of three groups ("n" less than or equal to 105) and up to 10 in each of four groups ("n" less than or equal to 40). They compared the exact distributions to the chi-square, gamma, and beta approximations. The beta approximation was best in…

This paper and the accompanying tool are intended to complement existing supports for conducting power analysis tools by offering a tool based on the framework of Minimum Detectable Effect Sizes (MDES) formulae that can be used in determining sample size requirements and in estimating minimum detectable effect sizes for a range of individual- and…

Purpose: The aim of this research is to investigate the effect of Augmented Reality (AR) applications in the learning process. Problem: Research that determines the effectiveness of Augmented Reality (AR) applications in the learning process with different variables has not been encountered in national or international literature. Research…

Different estimation procedures have been developed for the unidimensional three-parameter item response theory (IRT) model. These techniques include the marginal maximum likelihood estimation, the fully Bayesian estimation using Markov chain Monte Carlo simulation techniques, and the Metropolis-Hastings Robbin-Monro estimation. With each…

The aim of this study is to determine the trend concerning interaction in distance education between the years 2011 and 2015. According to this aim, 544 articles in the databases of EBSCO, Scopus, and Web of Science were examined. The examination has been conducted on the basis of various variables including year, country, number of authors,…

Employing an existing database of African American and biracial children entering metropolitan Detroit schools, we examined children of caregivers with and without reported stressful police contact. As anticipated, young children of caregivers with recent stressful police contact appear to suffer cognitive performance decrements on a nonverbal…

Purpose: The Expository Scoring Scheme (ESS) is designed to analyze the macrostructure of descriptions of a favorite game or sport. This pilot study examined inter- and intrarater reliability of the ESS and use of the scale to capture developmental change in elementary school children. Method: Twenty-four children in 2 language groups (monolingual…

The design of research studies utilizing binary multilevel models must necessarily incorporate knowledge of multiple factors, including estimation method, variance component size, or number of predictors, in addition to sample sizes. This Monte Carlo study examined the performance of random effect binary outcome multilevel models under varying…