A common motivation for adding control variables to statistical models is to reduce the potential for spurious findings when analyzing non-experimental data and to thereby allow for more reliable causal inferences. However, as I show here, unless "all" potential confounding factors are included in an analysis (which is unlikely to be…

This toolkit, developed by Regional Educational Laboratory (REL) Central in collaboration with York Public Schools in Nebraska, provides a process and tools to help teachers use data from their classroom assessments to evaluate promising practices. The toolkit provides teachers with guidance on how to deliberately apply and study one classroom…

Students learn or progress at their own paces. Each needs different amounts of support, at different points in a school career and at different times of the school year. Some need very little help to stay on track, while others are facing serious challenges in learning, in their behavior, or at home, and need significant interventions. It would…

This addendum to previously published results presents alternative analyses of data from large-scale effectiveness studies of Cognitive Tutor Algebra I in middle schools and high schools. These alternative analyses produce results that are substantively the same as previously reported. We find a significant positive effect of 0.21 standard…

This report summarizes the findings of an analysis of a series of action research projects conducted by Goshen Community Schools at the elementary, middle, and high school levels. During the 2008-2009 school year, 40 teachers participated in independent action research studies regarding the extent to which a six step approach to direct vocabulary…

Toddlers in the lowest 10th percentile for lexical production were compared with age- and language-matched controls on measures of phonetic complexity, lexical development, and grammatical complexity. Results indicate an overlap between phonology, lexicon, and grammar and suggest the importance of true consonant production for lexical development.…