Students with Attention-Deficit/Hyperactivity Disorder (ADHD) are struggling writers. Yet no comprehensive model has been validated to explain their poor writing outcomes. This study aims to test whether an extended version of the Not-So-Simple View of Writing (NSVW) model can describe the effects of key abilities on writing performance in…

Despite broad applications of growth curve models, few studies have dealt with a practical issue -- nonnormality of data. Previous studies have used Student's "t" distributions to remedy the nonnormal problems. In this study, robust distributional growth curve models are proposed from a semiparametric Bayesian perspective, in which…

Few studies have examined the relation between maternal caloric intake during pregnancy and growth in child academic achievement while controlling for important confounding influences. Using data from the National Longitudinal Survey of Youth, the current study examined the effects of reduced prenatal caloric intake on growth in scores on the…

Gough and Tunmer's (1986) simple view of reading (SVR) proposed that reading comprehension (RC) is a function of language comprehension (LC) and word recognition/decoding. Braze et al. (2007) presented data suggesting an extension of the SVR in which knowledge of vocabulary (V) affected RC over and above the effects of LC. Tunmer and Chapman…

This study examines the genetic and environmental etiology underlying the development of oral language and reading skills, and the relationship between them, over a long period of developmental time spanning middle childhood and adolescence. It focuses particularly on the differential relationship between language and two different aspects of…

The current study tested a multiple-cognitive predictor model of word reading, math ability, and attention in a community-based sample of twins ages 8 to 16 years (N = 636). The objective was to identify cognitive predictors unique to each skill domain as well as cognitive predictors shared among skills that could help explain their overlap and…

Growth curve models with different types of distributions of random effects and of intraindividual measurement errors for robust analysis are compared. After demonstrating the influence of distribution specification on parameter estimation, 3 methods for diagnosing the distributions for both random effects and intraindividual measurement errors…

This study examined whether a large group of postsecondary students participating in a support program for students classified as having learning disabilities (LD) met criteria for five objective diagnostic models for LD: IQ-achievement discrepancy (1.0 SD, 1.5 SD, and greater than 2.0 SD) models, a "Diagnostic and Statistical Manual of…

Prenatal and perinatal risk factors, such as low birth weight, have been linked to higher levels of aggressive and destructive behaviours during childhood. Although low birth weight is associated with childhood externalizing behaviour, the mechanisms underlying this relationship remain open to empirical investigation. The current study extends the…

Despite the widespread popularity of growth curve analysis, few studies have investigated robust growth curve models. In this article, the "t" distribution is applied to model heavy-tailed data and contaminated normal data with outliers for growth curve analysis. The derived robust growth curve models are estimated through Bayesian…

Several alternatives are available for specifying the residual structure in latent growth curve modeling. Two specifications involve uncorrelated residuals and represent the most commonly used residual structures. The first, building on repeated measures analysis of variance and common specifications in multilevel models, forces residual variances…

In this paper, we investigate the association between weight and children's educational achievement, as measured by scores on Peabody Individual Achievement Tests in math and reading, and grade attainment. Data for the study came from the 1979 cohort of the National Longitudinal Survey of Youth (NLSY), which contains a large, national sample of…

Policies governing divorce and parenting, such as child support orders and enforcement, child custody regulations, and marital dissolution requirements, can have a large impact on the welfare of parents and children. Recent research has produced evidence on the responses of divorce rates to unilateral divorce laws and child support enforcement. In…