Various studies have examined possible loci of deaf learners' documented challenges with regard to reading, usually focusing on language-related factors. Deaf students also frequently struggle in mathematics and science, but fewer studies have examined possible reasons for those difficulties. The present study examined numerical and non-numerical…

This study investigated developmental gender differences in mathematics achievement, using the child and adolescent portion (ages 6-19 years) of the Kaufman Test of Educational Achievement-Third Edition (KTEA-3). Participants were divided into two age categories: 6 to 11 and 12 to 19. Error categories within the Math Concepts & Applications…

Recent research has shown that over-extraction of latent classes can be observed in the Bayesian estimation of the mixed Rasch model when the distribution of ability is non-normal. This study examined the effect of non-normal ability distributions on the number of latent classes in the mixed Rasch model when estimated with maximum likelihood…

Arithmetic word-problem solving is an important component of elementary mathematics curricula that links school mathematics to real-life problem solving. The present 3-year longitudinal study examined children's arithmetic word-problem solving through understanding its 2 component processes: number-sentence construction and computation. Chinese…

The current study investigated college students' content knowledge and cognitive abilities as factors associated with their algebra performance, and examined how combinations of content knowledge and cognitive abilities related to their algebra performance. Specifically, the investigation examined the content knowledge factors of computational…

In large-scale educational surveys, a latent regression model is used to compensate for the shortage of cognitive information. Conventionally, the covariates in the latent regression model are principal components extracted from background data. This operational method has several important disadvantages, such as the handling of missing data and…

Three cohorts of third-grade students (N = 813) were evaluated on achievement, cognitive abilities, and behavioral attention according to contrasting research traditions in defining math learning disability (LD) status: low achievement versus extremely low achievement and IQ-achievement discrepant versus strictly low-achieving LD. We use methods…

Recent data have suggested that despite massive outlays on educational reform Qatar consistently ranks as one of the least academically proficient countries in key areas of literacy. Of the seventy-four countries that participated in PISA 2009 Qatar ranked between sixty-seven and sixty-nine in mathematics, reading and science literacy. Although…

In organizational studies involving multiple levels, the association between a covariate and an outcome often differs at different levels of aggregation, giving rise to widespread interest in "contextual effects models." Such models partition the regression into within- and between-cluster components. The conventional approach uses each…

To test the theory of mental calibration for mental addition it was hypothesized that the mean reaction time for problems in homogeneous sets will be faster than for problems in heterogeneous sets and that the reaction time was inversely related to ability and development (grade level) and independent of gender. Three sets of 40 addition problems…