Multisite trials, in which individuals are randomly assigned to alternative treatment arms within sites, offer an excellent opportunity to estimate the cross-site average effect of treatment assignment (intent to treat or ITT) "and" the amount by which this impact varies across sites. Although both of these statistics are substantively…

A number of studies of parent-mediated interventions in autism spectrum disorder have been published in the last 15 years. We reviewed 19 randomized clinical trials of parent-mediated interventions for children with autism spectrum disorder between the ages of 1 and 6 years and conducted a meta-analysis on their efficacy. Meta-analysis outcomes…

Researchers may have multiple motivations for combining disparate pieces of evidence in a meta-analysis, such as generalizing experimental results or increasing the power to detect an effect that a single study is not able to detect. However, while in meta-analysis, the main question may be simple, the structure of evidence available to answer it…

In 2013-14, the Wake County Public School System (WCPSS) launched Achieve3000 as a randomized controlled trial in 16 elementary schools. Achieve3000 is an early literacy program that differentiates non-fiction reading passages based on individual students' Lexile scores. Twoyear results show that Achieve3000 did not have a significant impact on…

Background: Selective outcome and analysis reporting (SOR and SAR) occur when only a subset of outcomes measured and analyzed in a study is fully reported, and are an important source of potential bias. Key methodological issues: We describe what is known about the prevalence and effects of SOR and SAR in both randomized controlled trials (RCTs)…

This paper describes a randomised controlled trial conducted with 10 secondary schools in England to evaluate the impact and feasibility of Fresh Start as an intervention to help new entrants with low prior literacy. Fresh Start is a synthetic phonics programme for small groups of pupils, here implemented three times per week over 22 weeks. The…

This paper uses the credits-attempted perspective--in the context of how many credits a student attempts in their first year of college--and reports on several related projects all intended to evaluate potential interventions to raise academic momentum among first-year community college students. The presentation contrasts non-experimental…

Recent work that has examined the impact of what are variously called periodic, interim, benchmark, or diagnostic assessments, typically administered three or four times during a school year, has produced mixed findings. For instance, one study reported small significant effects in mathematics in grades 3-8, but not in reading (Carlson et al.,…