Purpose: Individual differences in vocabulary development may affect academic or social opportunities. It has been proposed that individual differences in word reading could affect the rate of vocabulary growth, mediated by the amount of reading experience, a process referred to as a "Matthew effect" (Stanovich, 1986). Method: In the…

Little is known empirically about intraclass correlations (ICCs) for multisite cluster randomized trial (MSCRT) designs, particularly in science education. In this study, ICCs suitable for science achievement studies using a three-level (students in schools in districts) MSCRT design that block on district are estimated and examined. Estimates of…

This study tested the theory that an authoritative school climate characterized by disciplinary structure and student support is conducive to positive academic outcomes for middle and high school students. Multilevel multivariate modeling at student and school levels was conducted using school surveys completed by statewide samples of 39,364…

A cluster-randomized trial (CRT) relies on random assignment of intact clusters to treatment conditions, such as classrooms or schools (Raudenbush & Bryk, 2002). One specific type of CRT, a multi-site CRT (MSCRT), is commonly employed in educational research and evaluation studies (Spybrook & Raudenbush, 2009; Spybrook, 2014; Bloom,…

This study investigated bullying victims' perceptions of their teachers' support and monitoring when controlling for level of mental health problems, peer relationships, gender, and grade level. Given the nested structure of the data, multilevel analyses were employed to examine these associations. The quality of classroom interaction is highly…

Using a "naïve" specification, this paper estimates the relationship between 36 high school characteristics and 24 student outcomes controlling for students' pre-high school characteristics. The goal of this exploration is not to generate casual estimates, but rather to: (a) compare the size of the relationships to determine which inputs…

This paper investigates the validity of a national, standards-based teacher evaluation programme by examining the relationship between teachers' evaluation results and their students' learning progress. We used census achievement data that assessed the same cohort of students at the end of 8th and 10th grade. We applied multilevel modelling and…

In this study, students' understanding of chemical changes was investigated in relation to four individual differences, related to logical thinking, field dependence/independence, convergence and divergence thinking. The study took place in Greece with the participation of students (n = 374) from three grades (8th, 10th and 12th grades) of…

Background: Deficient vocabulary is a frequently reported symptom of developmental language impairment, but the nature of the deficit and its developmental course are not well documented. Aims: To describe the nature of the deficit in terms of breadth and depth of vocabulary knowledge and to determine whether the nature and the extent of the…

In longitudinal education studies, assuming that dropout and missing data occur completely at random is often unrealistic. When the probability of dropout depends on covariates and observed responses (called "missing at random" [MAR]), or on values of responses that are missing (called "informative" or "not missing at random" [NMAR]),…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…