In this study, we examined the extent to which teachers' treatment adherence, instructional quality, and the interaction of these variables influenced eighth-grade students' content knowledge and reading comprehension. We examined treatment fidelity for students (n = 775) in classes randomly assigned to receive an evidence-based content area…

The purpose of this study was to examine associations between implementation fidelity of school-wide positive behavioral interventions and supports (SWPBIS) and student outcomes over time. The sample included 477 K-12 schools across 10 states implementing SWPBIS for varying numbers of years and at varying levels of fidelity (but with 78% of…

This study documents the process of implementation of an adolescent reading intervention. Using data from observations of teachers (n=17) during the 2013-14 school year, I conducted a nuanced descriptive analysis of fidelity of implementation (FoI). I also analyzed weekly logs completed by literacy coaches (n=3) to examine variation in quantity…

Data from a large-scale math intervention program were used to evaluate the degree to which implementation fidelity (IF) and interventionist content knowledge were associated with student outcomes. Data were available for 33 interventionists serving 658 students in Grades 4-6 across one school year. A series of multilevel models were fit to the…

The present article reports results of a real-world effectiveness trial conducted in Denmark with six thousand four hundred eighty-three 3- to 6-year-olds designed to improve children's language and preliteracy skills. Children in 144 child cares were assigned to a control condition or one of three planned variations of a 20-week storybook-based…

"Un Buen Comienzo" [A Good Start] was a professional development program implemented with prekindergarten and kindergarten teachers in Chilean public schools serving low-income families. In a randomized trial, the program showed moderate to large impacts on classroom quality but no impacts on targeted child outcomes. To unpack these…

Multilevel modeling techniques facilitated examination of relationships between fidelity indicators and outcomes associated with a summer literacy intervention. Three-level growth models were specified to capture the extent to which students experienced instruction and to demonstrate the ways in which dosage-response relationships manifest in…