Effect sizes are critical to result interpretation and synthesis across studies. Although statistical significance testing has historically dominated the determination of result importance, modern views emphasize the role of effect sizes and confidence intervals. This article accessibly discusses how to calculate and interpret the effect sizes…

This meta-analysis reviews 208 laboratory studies of acute psychological stressors and tests a theoretical model delineating conditions capable of eliciting cortisol responses. Psychological stressors increased cortisol levels; however, effects varied widely across tasks. Consistent with the theoretical model, motivated performance tasks elicited…

A meta-analysis of 95 studies was conducted to investigate the relations of heart rate (HR) and electrodermal activity (EDA) with aggression, psychopathy, and conduct problems. Analyses revealed a complex constellation of interactive effects, with a failure in some cases of autonomic patterns to generalize across antisocial spectrum behavior…

I studied rater effects in the writing and speaking sections of the Test of German as a Foreign Language (TestDaF). Building on the many-facet Rasch measurement methodology, the focus was on rater main effects as well as 2- and 3-way interactions between raters and the other facets involved, that is, examinees, rating criteria (in the writing…

This meta-analysis investigated the influence of assessment on the reported effects of problem-based learning (PBL) by applying Sugrue's (1995) model of cognitive components of problem solving. Three levels of the knowledge structure that can be targeted by assessment of problem solving are used as the main independent variables: (a) understanding…

The last two decades have witnessed a surge in interest in research on organizational identification (OI). This paper presents a comprehensive meta-analysis of this research (k=96). Results indicate that (a) OI is correlated with a wide range of work-related attitudes, behaviors, and context variables, (b) OI is empirically distinct from its…

The author comments on the article "The Primacy of Cognition in Schizophrenia," by R. W. Heinrichs and states that to the pursuit of schizophrenic/normal differences, there is no end. Heinrichs used meta-analyses to argue persuasively for the primacy of cognition for this role. His conclusion not only elicited agreement from both researchers and…

This study is intended to review some of the selected researches carried out on students' understandings of enthalpy and spontaneity. The review puts together the important findings of the researches, summarises the misunderstandings identified so far and the possible sources of these misunderstandings. Therefore, this study would be beneficial…

This is a compilation of two separate reports on international literacy research from France and Argentina. In the reports from France, research correspondent Jacques Fijalkow detailed three research projects that included the following: (1) A description of adult literacy skills; (2) An investigation of how study-abroad students were integrated…

One lasting legacy of the effective schools movement was the institutionalization of the term "instructional leadership" into the vocabulary of educational administration. Evidence from other recent reviews of the literature on principal leadership (e.g., Hallinger, 2001; Hallinger & Heck 1996; Southworth, 2002) suggest that twenty…

In this article we briefly examine the meta-analysis of systematic phonics instruction published in "Teaching Children to Read," the influential 2000 report by the National Reading Panel. A brief review of this study, and the ensuing reanalysis by Camilli, Vargas, and Yurecko, is given. Following this, we report new analyses that…

Many primary studies have been performed to reveal the effects of computer assisted instruction (CAI) on students' attitudes towards science courses. In determining the effectiveness of these studies, gathering and evaluating of the studies at some characteristics play an important role. The aim of this study is to determine meta-analytically the…

This article explores the applicability of interdisciplinary research on the implementation of technological innovations to the field of e-learning research. Arguing that there are important ways in which e-learning systems can be treated as "technological innovations," this article presents a review of several key theoretical and research design…

The current meta-analysis reviews research on the treatment of pediatric obesity focusing on studies that have been published since 1994. Eleven studies (22 comparisons, 115 effect sizes, N = 447) were included in the present meta-analysis. Results indicated that comprehensive behavioral interventions may be improved in at least two ways:…

This article reports on a comprehensive literature review and meta-analysis of 68 experiments on teaching mathematics to individuals with significant cognitive disabilities. Most of the studies in the review addressed numbers and computation or measurement. Within the computation studies identified, most focused on counting, calculation, or number…