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…

Researchers and data analysts are sometimes faced with the problem of very small samples, where the number of variables approaches or exceeds the overall sample size; i.e. high dimensional data. In such cases, standard statistical models such as regression or analysis of variance cannot be used, either because the resulting parameter estimates…

We investigated sex effects and the effects of educational attainment (EA) on the covariance structure of the WAIS-III in a subsample of the Spanish standardization data. We fitted both first order common factor models and second order common factor models. The latter include general intelligence ("g") as a second order common factor.…