Mixture IRT models address the heterogeneity in a population by extracting latent classes and allowing item parameters to vary between latent classes. Once the latent classes are extracted, they need to be further examined to be characterized. Some approaches have been adopted in the literature for this purpose. These approaches examine either the…

This report presents a review of the statistical practices of 30 journals representative of the second language field. A review of 150 articles showed a number of prevalent statistical violations including incomplete reporting of reliability, validity, non-significant results, effect sizes, and assumption checks as well as making inferences from…

The study examined the various means of solving contradictions of predictive studies of University Matriculation Examination in Nigeria. The study used a sample size of 35 studies on predictive validity of University Matriculation Examination in Nigeria, which was purposively selected to have met the criteria for meta-analysis. Two null hypotheses…

Elicited imitation (EI) has been widely used to examine second language (L2) proficiency and development and was an especially popular method in the 1970s and early 1980s. However, as the field embraced more communicative approaches to both instruction and assessment, the use of EI diminished, and the construct-related validity of EI scores as a…

This study is an examination of the incremental validity of Cattell-Horn-Carroll (CHC) broad clusters from the Woodcock-Johnson III Tests of Cognitive Abilities (WJ III COG) for predicting scores on the Woodcock-Johnson III Tests of Achievement (WJ III ACH). The participants were children and adolescents, ages 6-18 (n = 4,722), drawn from the WJ…

The Implicit Association Test (IAT) is increasingly used in developmental research despite minimal evidence of whether children's IAT scores are reliable across time or predictive of behavior. When test-retest reliability and predictive validity have been assessed, the results have been mixed, and because these studies have differed on many…

Nonoverlap is widely used as a statistical summary of data; however, these analyses rarely correct unwanted positive baseline trend. This article presents and validates the graph rotation for overlap and trend (GROT) technique, a hand calculation method for controlling positive baseline trend within an analysis of data nonoverlap. GROT is…

Proactive preliminary minimum sample size determination can be useful for the early planning stages of a latent variable modeling study to set a realistic scope, long before the model and population are finalized. This study examined existing methods and proposed a new method for proactive preliminary minimum sample size determination.

Problem Statement: The number of studies on the effect of educational leadership on several organizational outputs is increasing. The most popular topic to review within the framework of leadership is job satisfaction. In several studies, a positive correlation was found between leadership and job satisfaction. According to the two-factor theory…

The main purpose of this study is to determine the effect of multiple intelligences theory (MIT)-based education on students' academic achievement. In this research, the meta-analytic method was adopted to determine this effect, and studies related to this subject carried out in Turkey were compiled. The effect sizes of the studies included in the…

The aim of the present study is to determine the influence of student-centered methods employed in Turkish language instruction on the academic success of students through meta-analysis. To this end, a literature review was conducted on the relevant studies conducted between 2000 and 2016 in order to determine the studies were suitable for the…

Visual display of reported impacts is a valuable aid to both reviewers and readers of systematic reviews. Forest plots are routinely prepared to report standardised effect sizes, but where standardised effect sizes are not available for all included studies a forest plot may misrepresent the available evidence. Tabulated data summaries to…

Fundamentally concerned with motivation, self-determination theory (SDT) represents a framework of several mini-theories to explore how social context interacts with people's motivational types categorized by degree of regulation internalization. This paper aims to modify an existing theory-based instrument (Academic Motivation Scale, or AMS) and…

This study explores the construct validity of speaking tasks included in the TOEFL iBT (e.g., integrated and independent speaking tasks). Specifically, advanced natural language processing (NLP) tools, MANOVA difference statistics, and discriminant function analyses (DFA) are used to assess the degree to which and in what ways responses to these…

The authors conducted a meta-analysis and systematic review that examined 23 studies evaluating the effectiveness of child centered play therapy (CCPT) conducted in elementary schools. Meta-analysis results were explored using a random effects model for mean difference and mean gain effect size estimates. Results revealed statistically significant…