Purpose: The purpose of this study was to document, validate, and corroborate effect size (ES) for single­-subject design in treatment of children with functional phonological disorders; to evaluate potential child-­specific contributing variables relative to ES; and to establish benchmarks for interpretation of ES for the population. Method: Data…

There is a noted advantage of dense neighborhoods in language acquisition, but the learning mechanism that drives the effect is not well understood. Two hypotheses--long-term auditory word priming and phonological working memory--have been advanced in the literature as viable accounts. These were evaluated in two treatment studies enrolling twelve…

The effects of the age of acquisition (AoA) of words were examined in the clinical treatment of 10 preschool children with phonological delays. Using a single-subject multiple-baseline experimental design, children were enrolled in one of four conditions that varied the AoA of the treated words (early vs. late acquired) relative to their…

The effect of word-level variables on expressive phonology has not been widely studied, although the properties of words likely bear on the emergence of sound structure (Stoel-Gammon, 2011). Eight preschoolers, diagnosed with phonological delay, were assigned to treatment to experimentally induce gains in expressive phonology. Erred sounds were…

The purpose of this article is to motivate the use of effect size (ES) for single-subject research in clinical phonology, with an eye towards meta-analyses of treatment effects for children with phonological disorders. Standard mean difference (SMD) is introduced and illustrated as one ES well suited to the multiple baseline (MBL) design and…

Purpose: To evaluate the effects of using nonword (NW) stimuli in treatment of children with phonological disorders relative to real words (RWs). Methods: Production data from 60 children were examined retrospectively. Thirty of the participants were previously treated on sounds in error using NWs, and the other 30 had been treated using RWs.…

Error patterns in children's phonological development are often described as simplifying processes that can interact with one another with different consequences. Some interactions limit the applicability of an error pattern, and others extend it to more words. Theories predict that error patterns interact to their full potential. While specific…

The purpose was to evaluate the lexicality of treated stimuli relative to phonological learning by preschool children with functional phonological disorders. Four children were paired in a single-subject alternating treatments design that was overlaid on a multiple baseline across subjects design. Within each pair, one child was taught one sound…

This paper describes a matrix for clinical use in the selection of phonological treatment targets to induce generalization, and in the identification of probe sounds to monitor during the course of intervention. The matrix appeals to a set of factors that have been shown to promote phonological generalization in the research literature, including…

This article documents the typological occurrence and interactions of two seemingly independent error patterns, namely Velar Fronting and Labial Harmony, in a cross-sectional investigation of the sound systems of 235 children with phonological delays (ages 3;0 to 7;9). The results revealed that the occurrence of Labial Harmony depends on the…

Statistical regularities in language have been examined for new insight to the language acquisition process. This line of study has aided theory advancement, but it also has raised methodological concerns about the applicability of corpora data to child populations. One issue is whether it is appropriate to extend the regularities observed in the…

Purpose: To extend formal models of language learnability to applications in clinical treatment of children with functional phonological delays. Method: The focus of the narrative review is on phonological complexity. This follows from learnability theory, whereby complexity in the linguistic input to children has been shown to trigger language…

The relationship between perception and production remains an unresolved issue within the study of phonological acquisition. Recent developments in optimality theory offer potentially new solutions to this long-standing problem; but thus far, the proposals that have been advanced are in the absence of actual perception-production data from a given…

Investigated children's abilities to conceptualize distinctive phonological features in development, studying relationships between productive and conceptual knowledge and the influence on phonological change. Young children with phonological disorders were evaluated, given treatment for producing accurate fricatives, then retested. Results…

Three studies of phonological knowledge and generalization were conducted with six functionally misarticulating children, aged 3-4. Results indicated that productive phonological knowledge of the sound system influenced the amount of generalization learning. The extent of generalization learning was associated with the point on the knowledge…