Orthographic processing -- the ability to perceive, access, differentiate, and manipulate orthographic knowledge -- is essential when learning to recognize words. Despite its critical importance in literacy acquisition, the field lacks a tool to assess this essential cognitive ability. The goal of this study was to design a computer-based…

Fraction arithmetic facility is fundamental to learning more advanced math topics. However, attaining the ability to add and subtract fractions is hard for many students. The present longitudinal study examined students' growth on simple addition and subtraction word problems between fourth and sixth grades (N = 536). Latent class growth analyses…

The goal of the present article is to synthesize findings to date from the Delaware Longitudinal Study of Fraction Learning. The study followed a large cohort of children (N = 536) between Grades 3 and 6. The findings showed that many students, especially those with diagnosed learning disabilities, made minimal growth in fraction knowledge and…

The importance of fraction knowledge to later mathematics achievement, along with U.S. students' poor knowledge of fraction concepts and procedures, has prompted research on the development of fraction learning. In the present study, participants' (N = 536) development of fraction magnitude understanding and fraction arithmetic skills was assessed…

The present study examined the role of language capacities in explaining differences in social information processing (SIP) among three school-age groups: high-functioning children with autism spectrum disorder (ASD, IQ > 75), children with specific learning disorder (SLD), and children with typical development (TD). Participants were 96 boys…

This longitudinal study examined story-writing development of students from Grade 4 to Grade 6, comparing the developmental trajectories of English as a first language (EL1s; n = 43) and English learners (ELs; n = 108) in general, and in groups of EL1s and ELs with typically developing and poor reader profiles. In relation to their EL1 or EL…

The purpose of the present study was to reveal the developmental pathway from third grade cognitive competencies to sixth grade conceptual and procedural fraction knowledge through the intervening whole numerical skills at fifth grade. The study used empirical data that come from 536 students in nine schools across two Delaware public school…