The present study focuses on math and related skills among 32 girls with fragile X (n = 14) or Turner (n = 18) syndrome during late elementary school. Performance in each syndrome group was assessed relative to Full Scale IQ-matched comparison groups of girls from the general population (n = 32 and n = 89 for fragile X syndrome and Turner…

Determination of neuropsychological impairment involves contrasting obtained performances with a comparison standard, which is often an estimate of premorbid IQ. M. R. Schoenberg, R. T. Lange, T. A. Brickell, and D. H. Saklofske (2007) proposed the Child Premorbid Intelligence Estimate (CPIE) to predict premorbid Full Scale IQ (FSIQ) using the…

We estimate trends in intergenerational economic mobility by matching men in the Census to synthetic parents in the prior generation. We find that mobility increased from 1950 to 1980 but has declined sharply since 1980. While our estimator places greater weight on location effects than the standard intergenerational coefficient, the size of the…

Many students have difficulties with basic algebraic concepts at high school and at university. In this paper two levels of algebraic structure sense are defined: for high school algebra and for university algebra. We suggest that high school algebra structure sense components are sub-components of some university algebra structure sense…

This article describes an activity done by eighth grade students using data that was gathered from sun-shadow observations. (Contains 5 figures.)

This longitudinal study investigated the academic and cognitive characteristics of persistent mathematics difficulty (MD-p) from first to fourth grade. Ninety-nine children were retrospectively categorized into one of three groups: MD-p, transient mathematics difficulty (MD-t), or typically developing. MD-p was defined as persistently low…

This article shows how sixth graders engaged in authentic problem posing related to overcrowding at their school. Students posed authentic problems about their school space and then used mathematics as a tool to investigate and act on the situation. (Contains 6 figures.)

This study examines the mental computation strategies used by pupils at the end of primary school. In 1998 a new strategy for teaching mathematics was introduced into British schools (the National Numeracy Strategy) that specifically focused on mental calculation. The first part of the study took place in 1999, one year after the implementation of…

What is the nature of the association between age (7-11 years) and performance on mathematical equivalence problems (e.g., 7 + 4 + 5 + 7 + _)? Many prevailing theories suggest that there should be a positive association. However, change-resistance accounts (e.g., N. M. McNeil & M. W. Alibali, 2005b) predict a U-shaped association. The purpose of…

Many statistical tests are designed to test the different assumptions of the Rasch model, but only few are directed at detecting multidimensionality. The Martin-Lof test is an attractive approach, the disadvantage being that its null distribution deviates strongly from the asymptotic chi-square distribution for most realistic sample sizes. A Monte…

To reach a sustainable world the use of renewable energy sources is imperative. Photovoltaics (PV) is but one of the technologies that use the power of the sun and its deployment is growing very fast. Several master programs have been developed over the world, including Utrecht University, that teach these technologies. Within the framework of a…

We study four non-Newtonian fluid mechanics problems using Mathematica[R]. Constitutive equations describing the behavior of power-law, Bingham and Carreau models are recalled. The velocity profile is obtained for the horizontal flow of power-law fluids in pipes and annuli. For the vertical laminar film flow of a Bingham fluid we determine the…

At Florida Tech, we have incorporated DataFit from Oakdale Engineering throughout the entire curriculum, beginning with ChE 1102, an eight-week, one-day-per-week, two-hour, one-credit-hour, second-semester Introduction to Chemical Engineering course in a hands-on computer classroom. Our experience is that students retain data analysis concepts…

A biologically detailed computational model is described of how categorization judgments become automatic in tasks that depend on procedural learning. The model assumes 2 neural pathways from sensory association cortex to the premotor area that mediates response selection. A longer and slower path projects to the premotor area via the striatum,…

This Monte Carlo study examined the impact of misspecifying the [big sum] matrix in longitudinal data analysis under both the multilevel model and mixed model frameworks. Under the multilevel model approach, under-specification and general-misspecification of the [big sum] matrix usually resulted in overestimation of the variances of the random…