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…

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,…

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…

Effective instructional materials can be valuable interventions to improve student interest and achievement in science (National Research Council [NRC], 2007); yet, analyses indicate that many science instructional materials and curricula are fragmented, lack coherence, and are not carefully articulated through a sequence of grade levels (AAAS,…

Background: Chronotype refers to individuals' preference for morning or evening activities. Its two dimensions (morningness and eveningness) are related to a number of academic outcomes. Aims: The main goal of the study was to investigate the incremental validity of chronotype as a predictor of academic achievement after controlling for a number…