This dissertation begins with the observation of a typological asymmetry within phonological patterns related to phonetic naturalness. Patterns that are rooted within existing tendencies of perception and/or production--in other words, patterns that are phonetically "natural"--are common in phonological typology and seen in a variety of…

After multiple reviews of the literature, which documented that multiple cognitive processes may be involved in mathematics ability and disability, Geary (1993) proposed a model that included three subtypes of math disability: Semantic, Procedural, and Visuospatial. A review of the extant literature produced three studies that examined Geary's…

Texts are typically classified by researchers into one of two genres: narrative or expository. Narrative texts are meant to entertain (e.g., fictional novels and stories), while expository texts are meant to educate (e.g., text books and empirical articles) (Weaver & Bryant, 1995). One problem with this simple method for categorizing texts is that…

The Visual-Spatial Chemistry Specific (VSCS) assessment tool was developed to test students' visual-perceptual skills, which are required to form a mental image of an object. The VSCS was designed around the theoretical framework of Rochford and Archer that provides eight distinct and well-defined visual-perceptual skills with identified problems…

Working under classical test theory (CTT) and item response theory (IRT) frameworks, this study investigated psychometric properties of the Revised Purdue Spatial Visualization Tests: Visualization of Rotations (Revised PSVT:R). The original version, the PSVT:R was designed by Guay (1976) to measure spatial visualization ability in…