This paper reviews literature on the rationale, challenges, and recommendations for choosing a nonequivalent comparison (NEC) group design when evaluating intervention effects. After reviewing frequently addressed threats to validity, the paper describes recommendations for strengthening the research design and how the recommendations were…

For the 2014 study, "A Randomized Trial Examining the Effects of Aerobic Physical Activity on Attention-Deficit/Hyperactivity Disorder Symptoms in Young Children", researchers examined the effect of a daily before-school physical activity program on behavioral outcomes of students in grades K-2. The study sample included 202 students who…

Interest in variation in program impacts--How big is it? What might explain it?--has inspired recent work on the analysis of data from multi-site experiments. One critical aspect of this problem involves the use of random or fixed effect estimates to visualize the distribution of impact estimates across a sample of sites. Unfortunately, unless the…

In experimental studies, researchers are often interested in secondary research questions that explore important aspects of main findings, such as whether or not program effects vary according to the level of fidelity in which the program has been implemented; or according to the dosage received by individuals participated in the program. In this…

The use of educational technology in K-12 classrooms has been gaining tremendous momentum across the country since the 1990s. Many school districts have been investing heavily in various types of technology, such as computers, mobile devices, internet access, and interactive whiteboards. Almost all public schools have access to the internet and…

A Friedman Foundation report attempts to find empirical support for the contention that competition from private schools, through voucher programs, improves the effectiveness of public schools. In the first year of Ohio's new EdChoice voucher program, the report claims to have found substantial academic gains at public schools exposed to the…

This What Works Clearinghouse (WWC) topic report addresses reading interventions for students in grades K-3, including core reading curricula, programs, or products to be used as supplements to other reading instruction, programs that focus on staff development, and literacy software. The WWC review on beginning reading focuses on programs…