Designing and interpreting controlled experiments are important inquiry skills addressed in many current science curricula. The relevant skills associated with the design and interpretation of controlled experiments are summarised under the term control-of-variables strategy (CVS). Research on elementary school students' CVS skills shows that they…

This systematic review and meta-analysis appraised and synthesized mathematics interventions research addressing rational number concepts for students with mathematics difficulties (MD) in Grades 3-9. Included studies (n = 28) meet the What Works Clearinghouse Group Design standards (Version 4.0) for study quality. Across all studies, we found…

Programs that improve teaching effectiveness represent a core strategy to improve student educational outcomes and close student achievement gaps. This article compiles empirical values of intraclass correlations for designing effective and efficient experimental studies evaluating the effects of these programs. The Early Childhood Longitudinal…

Background: Special education services are individualized supports provided to students with disabilities (SWD) that should help them make appropriate educational progress given their abilities, educational needs, and goals (Endrew F. v. Douglas County School District, 2017). Concerns about the benefits of these services have emerged given the…

A key consideration in planning studies of community-based HIV education programs is identifying a sample size large enough to ensure a reasonable probability of detecting program effects if they exist. Sufficient sample sizes for community- or group-based designs are proportional to the correlation or similarity of individuals within communities.…

We develop a theoretical and empirical basis for the design of teacher professional development studies. We build on previous work by (a) developing estimates of intraclass correlation coefficients for teacher outcomes using two- and three-level data structures, (b) developing estimates of the variance explained by covariates, and (c) modifying…

An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated…

Inquiry science instruction is especially challenging in elementary grades where teachers are constrained by crowded curricula and time. Professional development (PD) may provide an opportunity to support elementary teacher development of inquiry science instruction. The study examines the inquiry practice of two teachers who participated in an…

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…

In this study, we examined the relationship between teachers' attitudes towards professional development and school performance in the state accountability system using the 2013 Kentucky Teaching, Empowering, Leading and Learning (TELL) survey data and the 2013 school accountability profile data from the Kentucky Department of Education. We were…

Data was collected from 403 primary school administrators in Maha Sarakham Province, Thailand, to develop causal relationship model of Administrator Characteristics (AC), Teacher Characteristics (TC) and Environmental Education Principle (EE) that affect Environmental Education Strategy (EES) through Inspiration of Public Mind for Environmental…

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,…

The aim of this study is to address and analyse pre-service teachers' mathematical reasoning skills in relation to mathematical thinking processes. For these purposes, pre-service teachers' mathematical reasoning skills namely generalising/abstraction/modelling, ratiocination, development and creative thinking skills and the relationships among…

The capacity of the field to conduct power analyses for group randomized trials (GRTs) of educational interventions has improved over the past decade (Authors, 2009). However, a power analysis depends on estimates of design parameters. Hence it is critical to build the empirical base of design parameters for GRTs across a variety of outcomes and…

This research study was conducted to examine the effects of the Kindergarten Readiness program in a large suburban school district in Tennessee as measured by third grade Reading and Mathematics TCAP Achievement Test scores. In addition, the study examined the relationships between the chronological ages of the students at kindergarten entry and…