Little research has been conducted on Arabic letter knowledge. This study investigates the nature of Arabic letter knowledge, its dimensionality, and the relative difficulty of letter knowledge items, all within an item response theory (IRT) framework. Three letter knowledge tests were administered to 142 native Arabic-speaking kindergarteners…

Complex research questions often need large samples to obtain accurate estimates of parameters and adequate power. Combining extant data sets into a large, pooled data set is one way this can be accomplished without expending resources. Measurement invariance (MI) modeling is an established approach to ensure participant scores are on the same…

Many students with reading difficulties and disabilities (RD) also have Attention Deficit/Hyperactivity Disorder (ADHD). This randomized clinical trial compared the effects of ADHD treatment alone (medication, parent training), intensive reading intervention alone, and their combination on the reading fluency and comprehension of students with…

Previous research has revealed conflicting results with regard to the role of the magnocellular visual system in reading and dyslexia. In order to investigate this further, the present study examined the relationship between performance on two magnocellular tasks (temporal gap detection and coherent motion), reading rate (oral and silent), and…

The purpose of this study was to examine construct validity of methods of calculating lexical diversity in written narrative samples relative to children's performance on a reading vocabulary measure. For 234 children in first to fifth grade, written narratives were examined and compared between grades for number of different words (NDW), total…

This study examined the effectiveness of the intensive implementation of a multicomponent reading intervention ("Voyager Passport") with 306 fourth-grade students with severe reading difficulties. Students with reading comprehension achievement below the 15th percentile in the fall of fourth grade were randomly assigned to the intensive…

In this large-scale study of students from Title 1 schools (N = 14,773), we used multiple-group latent change score (LCS) modeling to investigate the developmental relations between vocabulary knowledge and reading comprehension in students with a school-identified learning disability (LD; n = 627) and typically developing students (n = 14,146).…

This study examined the effectiveness of the intensive implementation of a multicomponent reading intervention (Voyager Passport) with 306 fourth grade students with severe reading difficulties. Students with reading comprehension achievement below the 15%ile in the fall of fourth grade were randomly assigned to the intensive intervention or to…

Purpose: The aims of the current project were twofold: (a) to describe the use of academic words in written language samples by fifth-grade students and (b) to examine the predictive relation between academic word use in academic writing and reading comprehension. Method: Investigators utilized written expository responses of 1,128 students in…

Recent research suggests that the etiology of reading achievement can differ across environmental contexts. In the US, schools are commonly assigned grades (e.g. "A," "B") often interpreted to indicate school quality. This study explored differences in the etiology of early literacy skills for students based on these school…

Research examining effective reading interventions for students with reading difficulties in the upper elementary grades is limited relative to the information available for the early elementary grades. In the current study, we examined the effects of a multicomponent reading intervention for students with reading comprehension difficulties. We…

Research examining effective reading interventions for students with reading difficulties in the upper elementary grades is limited relative to the information available for the early elementary grades. In the current study, we examined the effects of a multicomponent reading intervention for students with reading comprehension difficulties. We…

The present study employed data simulation techniques to investigate the 1-year stability of alternative classification schemes for identifying children with reading disabilities. Classification schemes investigated include low performance, unexpected low performance, dual-discrepancy, and a rudimentary form of constellation model of reading…

This study rank ordered the contributive importance of several predictors of listening comprehension for third, seventh, and tenth graders. Principal components analyses revealed that a three-factor solution with fluency, reasoning, and working memory components provided the best fit across grade levels. Dominance analyses indicated that fluency…

The present study used a randomized control trial to examine the effects of a widely used multicomponent Tier 2-type intervention, Passport to Literacy, on the reading ability of 221 fourth graders who initially scored at or below the 30th percentile in reading comprehension. Intervention was provided by research staff to groups of 4-7 students…