We are concerned with the unbiased estimation of a treatment effect in the context of non-experimental studies with grouped or multilevel data. When analyzing such data with this goal, practitioners typically include as many predictors (controls) as possible, in an attempt to satisfy ignorability of the treatment assignment. In the multilevel…

Hierarchical organization of schooling in all nations insures that international large-scale assessment data are multilevel where students are nested within schools and schools are nested within nations. Longitudinal follow-up of these students adds an additional level. Hierarchical or multilevel models are appropriate to analyze such data. A…

This study evaluated the effects of a mathematics software program, the Building Blocks software suite, on young children's mathematics performance. Participants included 247 Kindergartners from 37 classrooms in 9 schools located in low-income communities. Children within classrooms were randomly assigned to receive 21 weeks of computer-assisted…

These appendices accompany the report "Final Report of the i3 Impact Study of Making Sense of SCIENCE, 2016-17 through 2017-18." Science education has experienced a significant transition over the last decade, catalyzed by a re-envisioning of what students should know and be able to do in science. That re-envisioning culminated in the…

Many preschool language-focused interventions attempt to boost language and literacy skills in young children at risk in these areas of development, though the long-term effects of such interventions are not well-established. This study investigated kindergarten language and reading skills, specifically the subcomponents of vocabulary, decoding,…

This study examined the reading and math achievement profiles and longitudinal growth trajectories of a nationally representative sample of children ages 6 through 9 with an ASD. Four distinct achievement profiles were identified: higher-achieving (39%), hyperlexia (9%), hypercalculia (20%), and lower-achieving (32%). Children with hypercalculia…

We had 3 aims in the present study: (a) to examine the dimensionality of various evaluative approaches to scoring writing samples (e.g., quality, productivity, and curriculum-based measurement [CBM] writing scoring), (b) to investigate unique language and cognitive predictors of the identified dimensions, and (c) to examine gender gap in the…

Multilevel modeling techniques were used with a sample of 643 students enrolled in 37 secondary school classrooms to predict future student achievement (controlling for baseline achievement) from observed teacher interactions with students in the classroom, coded using the Classroom Assessment Scoring System--Secondary. After accounting for prior…

Intraclass correlations are used to summarize the variance decomposition in popula- tions with multilevel hierarchical structure. There has recently been considerable interest in estimating intraclass correlations from surveys or designed experiments to provide design parameters for planning future large-scale randomized experiments. The large…