Optimal design of multisite randomized trials leverages sampling costs to optimize sampling ratios and ultimately identify more efficient and powerful designs. Past implementations of the optimal design framework have assumed that costs of sampling units are equal across treatment conditions. In this study, we developed a more flexible optimal…

This rejoinder keeps the original focus on statistical computing pertaining to the correlation of student achievement between mathematics and science from the Trend in Mathematics and Science Study (TIMSS). Albeit the availability of student performance data in TIMSS and the emphasis of the inter-subject connection in the Next Generation Science…

Experience-sampling methods (ESM) enable us to learn about individuals' lives in context by measuring participants' feelings, thoughts, actions, context, and/or activities as they go about their daily lives. By capturing experience, affect, and action "in the moment" and with repeated measures, ESM approaches allow researchers…

Outdoor adventure education (OAE) has a long history of being credited with the personal and social development (PSD) of its participants. PSD is notoriously difficult to measure quantitatively, yet stakeholders demand statistical evidence that given approaches to eliciting PSD are effective in their methods. Rightly or wrongly, many stakeholders…

Mediation is a causal process that evolves over time. Thus, a study of mediation requires data collected throughout the process. However, most applications of mediation analysis use cross-sectional rather than longitudinal data. Another implicit assumption commonly made in longitudinal designs for mediation analysis is that the same mediation…

Childhood obesity is one of the most serious challenges of the 21st century and it is vital that evidence-based treatment approaches can be translated into practice to meet public health needs. Yet policy-makers cannot afford to wait for the results of lengthy trials before "probably efficacious" interventions are made available to the public, and…

This paper reports on a content analysis of 633 biology education research [BER] papers published by Turkish science educators in national and international journals. The findings indicate that more research has been undertaken in environment and ecology, the cell and animal form and functions. In addition learning, teaching and attitudes were in…

In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

Increasingly, qualitative researchers are combining methods, processes, and principles from two or more methodologies over the course of a research study. Critics charge that researchers adopting combined approaches place too little attention on the historical, epistemological, and theoretical aspects of the research design. Rather than…

The purpose of this review was to examine the methods used to conduct meta-analyses of single-subject research involving students with and at-risk for disabilities. Specifically, the procedures used for preparing, aggregating, analyzing, and evaluating single-subject data across 68 primary syntheses were examined. In addition to these…

Classroom context and climate are inherently classroom-level (L2) constructs, but applied researchers sometimes--inappropriately--represent them by student-level (L1) responses in single-level models rather than more appropriate multilevel models. Here we focus on important conceptual issues (distinctions between climate and contextual variables;…

The report, Yearning to Break Free: Ohio Superintendents Speak Out, describes findings of a survey of 246 Ohio school superintendents about critical issues facing the state's educational system. In particular, the intent of the study was to examine how superintendents might do more with fewer resources. The authors conclude that Ohio districts…

This paper provides a guide to calculating statistical power for the complex multilevel designs that are used in most field studies in education research. For multilevel evaluation studies in the field of education, it is important to account for the impact of clustering on the standard errors of estimates of treatment effects. Using ideas from…

A concern for generalization dominates quantitative research. For generalizability and repeatability, identification of sample size is essential. The present study investigates 90 qualitative master's theses submitted for the Primary and Secondary School Science and Mathematics Education Departments, Mathematic Education Discipline in 10…

Single subject research methodology is commonly used and cited in special education courses and journals. This article reviews the types of single subject research designs published in eight refereed journals between 1983 and 2007 used to answer applied research questions. Single subject designs were categorized as withdrawal/reversal, time…