Treatment efficacy has been a fruitful area of research in child phonology (Gierut, Morrisette, Hughes & Rowland, 1996). Linguistic models of phonological acquisition, structure, and change have been used to predict system level changes in children undergoing treatment for functional (i.e. nonorganic) phonological disorders. Most of the research has focused on establishing treatment paradigms that result in more ample changes to the child’s phonological system. One area that has received particular attention is the notion of markedness (Elbert, Dinnsen & Powell, 1984; Gierut et al., 1996). Markedness is best explained by universal patterns of use across languages. It usually refers to the relative complexity of a feature or segment, as compared to other features or segments. Unmarked features or segments are usually acquired before more marked features. They are also more frequently occurring across languages. Implicational universals are particularly relevant to the notion of markedness. In phonology, they indicate that the presence of certain sound classes or segments imply that other sound classes or segments are also present in the language (Elbert et al., 1984; Gierut et al., 1996). For example, the presence of fricatives in a language implies the presence of stops, but the presence of stops does not imply fricatives.