Children and adolescents spend considerable time online. The current study investigated moderators of short-term longitudinal associations from social media use to changes in body satisfaction and physical activity. Participants (144 girls, 152 boys) were third-sixth grade students (ages 8-13) attending public schools in Florida (USA).…

This study aimed to describe 1-year changes in students' vocabulary in written narratives. Secondary aims included examination of accuracy and the relationship between lexical diversity and achievement. Participants included 749 students in first through eighth grades. Within-subjects 1-year change in diversity, productivity, and accuracy was…

The objective of this study was to determine the latent profiles of reading and language skills that characterized 7,752 students in kindergarten through tenth grade and to relate the profiles to norm-referenced reading outcomes. Reading and language skills were assessed with a computer-adaptive assessment administered in the middle of the year…

We study the effects of various types of education and training on the ability of teachers to promote student achievement. Previous studies on the subject have been hampered by inadequate measures of teacher training and difficulties addressing the non-random selection of teachers to students and of teachers to training. We address these issues by…