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The PUBLICATIONS collection includes a bibliography of published work generated from the Learnability Project, with links to all manuscripts; this bibliography is also available in the BASICS collection. The PUBLICATIONS collection provides access to only those limited publications where permission was granted by the publisher for deposit in an institutional repository pursuant to copyright law.


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Now showing 1 - 20 of 66
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    Nexus to lexis: Phonological disorders in children
    (2016-03-20) Gierut, Judith A.
    Research on phonological disorders in children has conventionally emphasized the speech sound in search of causes, diagnoses, treatments and prevention of the disorder. This paper aims to shift the research focus to the word instead. The motivation comes from advances in psycholinguistics that demonstrate the word is central to the perception, production and acquisition of phonological information. Three strands of potential study are outlined in evaluation of how words might initiate and boost, but perhaps also, interrupt learning for children with phonological disorders.
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    Unraveling phonological conspiracies: A case study
    (Taylor & Francis, 2014) Dinnsen, Daniel A.; Gierut, Judith A.; Morrisette, Michele L.; Rose, Darcy E.
    This paper focuses on three seemingly unrelated error patterns in the sound system of a child with a phonological delay, Child 218 (male, age 4 years; 6 months) and ascribes those error patterns to a larger conspiracy to eliminate fricatives from the phonetic inventory. Employing Optimality Theory for its advantages in characterizing conspiracies, our analysis offers a unified account of the observed repairs. The contextual restrictions on those repairs are, moreover, attributed to early developmental prominence effects, which are independently manifested in another error pattern involving rhotic consonants. Comparisons are made with a published case study involving a different implementation of the same conspiracy, the intent being to disambiguate the force behind certain error patterns. The clinical implications of the account are also considered.
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    How to meet the neighbors: Modality effects on phonological generalization
    (Taylor & Francis, 2014) Gierut, Judith A.; Morrisette, Michele L.
    Long-term auditory priming of words from dense neighborhoods has been posited as a learning mechanism that affects change in the phonological structure of children’s lexical representations. An apparent confound associated with the modality of priming responsible for structural change has been introduced in the literature, which challenges this proposal. Thus, our purpose was to evaluate prime modality in treatment of children with phonological delay. Nine children were assigned to auditory-visual, auditory or visual priming of words from dense neighborhoods prior to treatment of production as the independent variable. The dependent variable was phonological generalization. Results showed that auditory priming (with or without visual input) promoted greater generalization on an order of magnitude of 3:1. Findings support the theoretical significance of auditory priming for phonological learning and demonstrate the applied utility of priming in clinical treatment.
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    Dense neighborhoods and mechanisms of learning: Evidence from children with phonological delay
    (Cambridge University Press, 2015) Gierut, Judith A.; Morrisette, Michele L.
    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 12 children with phonological delay. Study 1 exposed children to dense neighbors versus nonneighbors before training sound production in evaluation of the priming hypothesis. Study 2 exposed children to the same stimuli after training sound production as a test of the phonological working memory hypothesis. Results showed that neighbors led to greater phonological generalization than nonneighbors, but only when presented prior to training production. There was little generalization and no differential effect of exposure to neighbors or nonneighbors after training production. Priming was thus supported as a possible mechanism of learning behind the dense neighborhood advantage in phonological acquisition.
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    Learnability Project Publications / Bibliography
    (2017-01-09) Gierut, Judith A.
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    Effect size for single-subject design in phonological treatment
    (2015-07-20) Gierut, Judith A.; Morrisette, Michele L.; Dickinson, Stephanie
    Purpose: 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 were extracted from the Developmental Phonologies Archive for 135 preschool children with phonological disorders who previously participated in single-subject experimental treatment studies. Standard Mean DifferenceAll with Correction for Continuity was computed to gauge the magnitude of generalization gain that accrued longitudinally from treatment for each child, with the data aggregated for purposes of statistical analyses. Results: ES ranged from 0.09 to 27.83 for the study population. ES was positively correlated with conventional measures of phonological learning and visual inspection of learning data based on procedures standard to single-subject design. ES was linked to children’s performance on diagnostic assessments of phonology, but not other demographic characteristics or related linguistic skills and nonlinguistic skills. Benchmarks for interpretation of ES were estimated as 1.4, 3.6, and 10.1 for small, medium, and large learning effects, respectively. Conclusion: Findings have utility for single-subject research and translation of research to evidence-based practice for children with phonological disorders.
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    The predictive power of optimality theory for phonological treatment
    (Maney, 2008) Dinnsen, Daniel A.; Gierut, Judith A.
    The phonology and clinically induced learning patterns of a female child with a phonological delay (age 4;11) were examined from the analytical perspective of Optimality Theory. The analysis revealed that a Consonant Harmony error pattern affected alveolar stops from two different sources from underlying lexical representations and from representations derived by an interacting error pattern of Deaffrication. The implications of that analysis for the selection of treatment targets were explored in a treatment study. It was found that treatment aimed at the derived source of Consonant Harmony resulted in the suppression of both Consonant Harmony and Deaffrication. The explanation for these results was attributed to a fixed ranking among certain constraints.
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    Triggering a principle of phonemic acquisition
    (Taylor & Francis Health Sciences, 1996) Gierut, Judith A.; Morrisette, Michele L.
    This experimental clinical study evaluated different treatment manipulations of the principle of Laryngeal-Supralaryngeal Cyclicity as a follow-up to Gierut (1994b). Laryngeal-Supralaryngeal Cyclicity states that the acquisition of phonemic distinctions will occur as a bivalent cycle with laryngeal and supralaryngeal distinctions emerging in turn. In this study, children with seemingly static phonemic systems participated in a treatment programme that introduced sequentially new distinctions to the inventory. One child was presented with alternating laryngeal and supralaryngeal properties consistent with the principle, whereas the other child was exposed only to consecutive supralaryngeal distinctions. Results indicated that the latter treatment condition triggered greater phonemic expansion, as based on the longitudinal course of emergent phonemic distinctions for each child. These findings were comparable to those of the earlier investigation, and have implications for treatment efficacy and theories of language acquisition.
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    Teaching and learning /θ/: A non-confound
    (Taylor & Francis Health Sciences, 1992) Gierut, Judith A.; Neumann, Heidi J.
    The purpose of this study was to replicate and extend the findings on the effectiveness of homonymous versus non-homonymous treatment approaches for children with phonological disorders, following Gierut (1991b). The present study was motivated by a potential confound noted in the previous report; namely, the specific sounds /θ, ð/ treated in the presumably less effective homonymous condition may have inhibited degree of phonological change. It was thus necessary to teach these more difficult, late-acquired interdental fricatives in the more effective non-homonymous treatment condition using identical methods and procedures. Results indicated that a non-homonymous teaching approach again motivated greater phonological change than a homonymous approach, regardless of sounds that were taught. These findings have implications for the independence of linguistic structures of treatment in inducing sound change, and bear upon assumptions about ease of sound learning based on normative developmental sequences.
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    Geometric accounts of consonant-vowel interactions in developing systems
    (Taylor & Francis Health Sciences, 1993) Gierut, Judith A.; Cho, Mi-Hui; Dinnsen, Daniel A.
    Phenomena associated with consonant-vowel interactions are examined relative to three general models of feature geometry which differ in the planar relationship of consonants and vowels. The data come from reports of developing phonological systems, both normal and disordered. Geometric analyses reveal that consonants and vowels are fully integrated in the earliest stages of development such that the place specification of consonants is primarily derived from the vowel. However, change through development requires modifications either in the principles of place association, the degree of feature specification, or the planar representation of consonants and vowels.
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    Homonymy in phonological change
    (Taylor & Francis Health Sciences, 1991) Gierut, Judith A.
    This study examines the role of homonymy as a motivator of phonological change in treatment. The relative effectiveness of two treatment structures in improving the production of treated and untreated error sounds was evaluated. One treatment structure emphasized homonymous forms by comparing 1:1 a desired ambient target with its corresponding replacement error from the child's grammar, consistent with conventional minimal pair treatment (Weiner, 1981). The other treatment did not focus on homonymy, nor did it make explicit reference to a child's grammar. In line with treatment of the empty or unknown set (Gierut, 1989), two errored sounds were simply compared with each other. Differential learning was observed among the treatments such that the non-homonymous structure resulted in greater accuracies of treated sounds and in more new untreated sounds being added to the phonological system. The findings have potential implications for the status of homonymy in phonological change and in the structure of phonological treatment.
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    Spectral analysis of target-appropriate /t/ and /k/ produced by phonologically disordered and normally articulating children
    (Taylor & Francis Health Sciences, 1994) Forrest, Karen; Weismer, Gary; Elbert, Mary; Dinnsen, Daniel A.
    Previous research (Forrest, Weismer, Hodge, Dinnsen and Elbert, 1990) has shown that some phonologically disordered children differentially mark seemingly homophonous phonemes; however, the resulting contrast may be spectrally distinct from that produced by normally articulating children of the same age. In the present investigation possible sources for these differences between normally articulating and phonologically disordered children's productions of target-appropriate phonemes were pursued. Spectral characteristics of seemingly correct productions of /t/ and /k/ in word-initial position were analysed for four normally articulating and seven phonologically disordered children to assess the effect of recency of acquisition, depth of knowledge of the contrast and/or the effect of a phonological disorder on accuracy and variability of production. Results revealed that children who had acquired the velar-alveolar contrast more recently, and who had incomplete knowledge of that contrast, produced target-appropriate /t/ and /k/ differently from their normally articulating peers and other phonologically disordered children with greater knowledge of the contrast. Further, the phonologically disordered children with incomplete knowledge of the velar-alveolar contrast were less variable than the other phonologically disordered or normally articulating children in the spectral characteristics across repeated productions. Analysis of the spectral characteristics of word-initial /t/ and /k/ at a later point in time indicated similarities between all speaker groups in the spectral parameters that distinguished the velar from the alveolar stop. However, the stability of these parameters across repeated productions decreased for the phonologically disordered children with greater knowledge of the contrast. These effects are related to motor skill development and found to be consistent with previously demonstrated patterns of skill acquisition.
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    Feature geometry in disordered phonologies
    (Taylor & Francis Health Sciences, 1991) Chin, Steven B.; Dinnsen, Daniel A.
    Two types of systems are in general use for the description and classification of consonants in disordered phonological systems: conventional place-voice-manner and standard distinctive features. This paper proposes the use of a third model, feature geometry, which is an analysis framework recently developed in the linguistic study of primary languages. Feature geometry allows for relatively independent behaviour of individual distinctive features, but also organizes them into hierarchies in order to capture the fact that features very often act together in rules. Application of the feature geometry to the study of the phonologies of 40 misarticulating children, specifically to the phenomena of apparent cluster coalescence, fricative/affricate alternations, and alveolar stop/glottal stop alternations, reveals that feature geometry provides better explanations for representations and rules in disordered systems than either of the other two frameworks.
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    Natural domains of cyclicity in phonological acquisition
    (Taylor & Francis Health Sciences, 1998) Gierut, Judith A.
    This study expands and further validates cyclicity in the course of phonological development by exploring a potential relationship between the acquisition of singletons and clusters. The hypothesis is that children will acquire singletons followed by clusters in an alternating and recursive pattern, in complement to observed subsegmental cyclicity involving larnygeal and supralaryngeal distinctions. Six children with functional phonological disorders participated in one of three experimental conditions administered as a staggered multiple-baseline, multiple-probe design: treatment of singletons only, clusters only, or the singleton-cluster cycle. Results indicated that a singleton-cluster cycle could be induced experimentally, but it was not generally sustained by a child in expansion of the phonological repertoire. In comparison, laryngeal-supralaryngeal cyclicity was consistently maintained by all children, independent of experimental condition. A theoretical implication of these findings is that cyclicity functions as a governing principle of phonological development, but only if it is inherent to the natural domain of language. The clinical application of cyclicity in structuring treatment is considered.
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    Impact of substitution patterns on phonological learning by misarticulating children
    (Taylor & Francis Health Sciences, 1997) Forrest, Karen; Elbert, Mary; Dinnsen, Daniel A.
    Learning and generalization of treated sounds to different word positions is a desired outcome of intervention in the phonologically disordered child's system. Unfortunately, children do not always learn the sounds that is treated; nor do they always demonstrate across-word generalization. One possible explanation for differences in treatment outcome may relate to the pretreatment substitution patterns used by different disordered children. This post-hos analysis of treatment data examines the effects of sound learning and generalization of consistent versus inconsistent substitutes. With a consistent substitute across-word position (CS), the same phone was used in initial, medial and final position for a phoneme that was not in the child's inventory. An inconsistent substitute was evidenced by a different phone for a target sound in each position of a world (InAP), or even within word position (InWP) for an error sound. Fourteen children with severe phonological disorders were treated on an obstruent in initial or final word position. Seven of these children had a consistent substitute for the treated obstruent, two children had variable substitutes across word position, and five children had variable substitutes within and across word position. The analysis revealed a tight relationship between pretreatment substitution patterns and learning. The seven children with a consistent substitute for an error sound learned the sound targeted in treatment and generalized this knowledge to other word positions. Children who had variable substitutes across word position learned the treated sound, but only in the treated word position. Four of the five children in the InWP group did not learn to produce the sound targeted in treatment in any word position. These results suggest the pretreatment substitution patterns may be a predictor of learning and generalization in phonologically disordered children.
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    Statistical analysis of word-initial /k/ and /t/ produced by normal and phonologically disordered children
    (Taylor & Francis Health Sciences, 1990) Forrest, Karen; Weismer, Gary; Hodge, Megan; Elbert, Mary; Dinnsen, Daniel A.
    The acoustic characteristics of voiceless velar and alveolar stop consonants were investigated for normally articulating and phonologically disordered children using spectral moments. All the disordered children were perceived to produce It/ for /k/, with /k/ being absent from their phonetic inventories. Approximately 82% of the normally articulating children's consonants were classified correctly by discriminant function analysis, on the basis of the mean (first moment), skewness (third moment) and kurtosis (fourth moment) derived from the first 40 ms of the VOT interval. When the discriminant function developed for the normally articulating children was applied to the speech of the phonologically disordered group of children, no distinction was made between the velar and alveolar stops. Application of the model to the speech of individual children in the disordered group revealed that one child produced distinct markings to the velar-alveolar contrast. Variability measures of target /t/ and /k/ utterances indicated greater variability in this disordered child's productions compared with the normally articulating children. Phonological analysis of this child's speech after treatment, in which the velar-alveolar contrast was not treated, revealed target appropriate productions of both It/ and /k/. By contrast, the other three phonologically disordered children, for whom no acoustic distinction was found between target It/ and target /k/, did not evidence any knowledge of the contrast after treatment with other target phonemes.
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    Long-distance place assimilation with an interacting error pattern in phonological acquisition
    (Taylor & Francis Health Sciences, 1997) Dinnsen, Daniel A.; Barlow, Jessica A.; Morrisette, Michele L.
    Two commonly occurring and independent error patterns in children's early speech are examined to determine how and to what extent they might interact. One error pattern replaces velar consonants with coronals, and the other replaces a coronal with a consonant that agrees in place of articulation with some other consonant elsewhere in the word. A range of interactions is observed within and across children with regard to whether the product of one error pattern can serve as the target of the other. The different interactions motivate different claims about the nature and substance of children's underlying representations, which in some cases may differ from those of the ambient system. An extension to underspecification theory is advanced which allows underlying representations to be radically underspecified and in certain cases also to be specified for a default feature.
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    Lexical characteristics of sound change
    (Taylor & Francis Health Sciences, 1999) Morrisette, Michele L.
    The purpose of this study was to determine the relationship between sound change and lexical structure in two children with functional phonological disorders. Specifically, the question of how sound change infuses through the developing lexicon was addressed. A chronology of phonemic acquisition for the children who participated has previously been documented. These archival data were now extended to evaluate lexical change relative to sounds acquired. Lexical change was examined through the parameters of neighbourhood density and word frequency. Results of this study revealed two converging patterns across children: (a) for each child there was one parameter (neighbourhood density or word frequency) of lexical change which held across all sounds acquired, and (b) for each child the alternative parameter patterned differentially by sound. This variability in lexical change was hypothesized to be associated with the relative degree of feature specification of the sounds acquired. This has theoretical implications for the overlay of phonological and lexical structure, and clinical potential for remediation of phonological disorders.
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    Phonological learning and lexicality of treated stimuli
    (Informa Healthcare, 2010) Gierut, Judith A.; Morrisette, Michele L.
    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 in real words and a second sound in non-words; for the other child of the pair, lexicality was reversed and counterbalanced. The dependent variable was production accuracy of the treated sounds as measured during the session-by-session course of instruction. Results indicated that production accuracy of the treated sound was as good as or better using non-word as opposed to real word stimuli. The clinical implications are considered, along with potential accounts of the patterns of learning.
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    Comparability of lexical corpora: Word frequency in phonological generalization
    (Informa Healthcare, 2007) Gierut, Judith A.; Dale, Rachel A.
    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 speech of adults to developing linguistic systems. The purpose of this paper is to establish the comparability of lexical corpora in accounting for behavioural effects of word frequency on children's phonological generalization. Four word frequency corpora were evaluated in comparison of child/adult and written/spoken sources. These were applied post-hoc to generalization data previously reported for two preschool children. Results showed that the interpretation of phonological generalization was the same within and across children, regardless of the corpus being used. Phonological gains were more evident in low than high frequency words. The findings have implications for the design of probabilistic studies of language acquisition and clinical treatment programmes.