To plan cluster-randomized trials with sufficient statistical power to detect intervention effects on student achievement, researchers need multilevel design parameters, including measures of between-classroom and between-school differences and the amounts of variance explained by covariates at the student, classroom, and school level. Previous…

Using a cluster randomized field trial, the present study tested whether 2 relevance interventions affected students' value beliefs, self-concept, and effort in math differently depending on family background (socioeconomic status, family interest (FI), and parental utility value). Eighty-two classrooms were randomly assigned to either 1 of 2…

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 present study investigated the effectiveness of two short relevance interventions (writing a text or evaluating quotations about the utility of mathematics) using a sample of 1,916 students in 82 math classrooms in a cluster randomized controlled experiment. Short-term and sustained effects (6 weeks and 5 months after the intervention) of the…

When teachers or instructors create computer-based learning environments, they often solely consider technical aspects of interactivity. As a consequence, learners' main role is to respond to requests of the learning environment (e.g. by answering multiple-choice questions). This aspect of interactivity is, however, not sufficient to understand…

In the study presented in this paper, we examined the possibility to scaffold mathematical modelling with strategies. The strategies were prompted using an instrument called "solution plan" as a scaffold. The effects of this step by step instrument on mathematical modelling competency and on self-reported strategies were tested using…

The present study examined the effectiveness of the oral history approach with respect to students' historical competence. A total of 35 ninth-grade classes (N = 900) in Germany were randomly assigned to one of four conditions--live, video, text, or a (nontreated) control group--in a pretest, posttest, and follow-up design. Comparing the three…

Early interventions aim at promoting a good mother-child relationship as basis for a good socio-emotional development, especially in high-risk populations, and at correcting already unfavorable patterns of interaction and are common today. Insecure attachment, both of the child and of the mother, has been identified as a risk factor for early…

Aims: The objective of this study was to evaluate the preventive effect of a clinic-based, emotionally arousing, negative information giving intervention on adolescents' protective and risk factors of smoking. Methods: Data of 563 students (18 schools) from a cluster randomized controlled trial conducted in Heidelberg, Germany (2010-2011) were…

A randomized control intervention study was conducted to evaluate the effects of the highly structured Heidelberg Parent-Based Language Intervention (HPLI). The outcomes of 43 children (n = 23 intervention, n = 20 control) who had been identified as late talkers during routine developmental check-ups carried out in pediatric practices at the age…

Learning environments commonly offer aids to address learners' lack of knowledge or skills. However, learners are not or sub-optimally using these aids when these are non-embedded or segregated (Aleven, Stahl, Schworm, Fischer, & Wallace, 2003; Clarebout & Elen, 2006). This lack of optimal usage has been related to variables as…