Whether selection processes contribute to group-level disparities or merely reflect pre-existing inequalities is an important societal question. In the context of observational data, researchers, concerned about omitted-variable bias, assess selection-contributing inequality via a kitchen-sink approach, comparing selection outcomes of…

A common motivation for adding control variables to statistical models is to reduce the potential for spurious findings when analyzing non-experimental data and to thereby allow for more reliable causal inferences. However, as I show here, unless "all" potential confounding factors are included in an analysis (which is unlikely to be…

The purpose of this study was to conduct a rigorous examination of co-enrollment of students in math remediation and college-level math. A quasi-experimental, posthoc design examined the outcomes and the relationships of two groups of students who participated in a pilot project the goal of which was to assess the co-enrolled model that is…

There is evidence that participating in physical exercise reduces stress and the risk of many physical maladies. Exercise is also correlated with higher levels of approach motivation, or a tendency to approach challenge as an opportunity for growth or improvement instead of an opportunity for failure. To date, most research on this relationship…

The Advancement Via Individual Determination (AVID) curriculum emphasizes writing, collaboration, organization, and reading to strengthen academic skills. High school students enrolled in AVID elective classes receive daily academic support, while enrolled in challenging classes such as Advanced Placement (AP). The purpose of this study was to…

This article draws upon the literature showing the benefits of high-quality preschools on child well-being to explore the role of household income on preschool attendance for a cohort of 3-to 6-year-olds in China using data from the China Health and Nutrition Survey, 1991-2006. Analyses are conducted separately for rural (N = 1,791) and urban…

The purpose of this study was to explore whether conceptual change predicted emotional and attitudinal change while learning about genetically modified foods (GMFs). Participants were 322 college students; half read a refutation text designed to shift conceptual knowledge, emotions, and attitudes, while the other half served as a control group.…

We investigated the phonological and surface subtypes of developmental dyslexia in light of competing predictions made by two computational models of single word reading, the Dual-Route Cascaded Model (DRC; Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001) and Harm and Seidenberg's connectionist model (HS model; Harm & Seidenberg, 1999). The…

Attrition occurs when members of the initial research sample are not part of the final analysis sample, such as due to missing data or leaving the study. Both the overall sample attrition and the differences in attrition between the groups can affect the statistical equivalence of the sample and create potential for bias. The WWC has given careful…

Young people with autism spectrum disorder (ASD) have a high prevalence (~40 %) of anxiety disorders compared to their non-ASD peers. It is unclear whether cognitive and biological processes associated with anxiety in ASD are analogous to anxiety in typically developing (TD) populations. In this study 55 boys with ASD (34 with a co-occurring…

Based on a one-year longitudinal experimental study with 3,782 kindergarten school children across 15 countries, this article examines the association between prayer and happiness. Results show that the post-test scores on the faces scale were higher for the participant group who had taken the prayer lessons vis-à-vis the comparison group.…

The purpose of the study was to investigate if academic and social self-concept and motivation to improve in academic school subjects mediated the negative effect of summative assessment (grades) for low-ability students' achievement in compulsory school. In two previous studies, summative assessment (grading) was found to have a differentiating…

This study analyzes the development of percentages knowledge by seventh graders given a sequence of activities starting with a realistic modeling task, in which students were expected to create a model that would facilitate the reinvention of percentages. In the first two activities, students constructed their own pricing model using fractions and…

In recent years, researchers have shown an increased interest in learner styles as one of the key factors influencing learning generally. During the last decade we have also noticed rapid advances in the field of technology enhanced learning and growing trend towards its application in formal education. Introduction of different forms of…

The present study reports on the findings of a cross-sectional acoustic study of the production of Spanish vowels by three different groups of speakers: 1) native Spanish speakers; 2) native English intermediate learners of Spanish; and 3) native English advanced learners of Spanish. In particular, we examined the production of the five Spanish…