Matching Items (2)
Description
Differentiating bilingual children with primary language impairment (PLI) from those with typical development in the process of learning a second language has been a challenge. Studies have focused on improving the diagnostic accuracy of language measures for bilinguals. However, researchers are faced with two main challenges when estimating the diagnostic accuracy of new measures: (a) using an a priori diagnosis of children (children with and without PLI), as a reference may introduce error given there is no gold standard for the a priori classification; and (b) classifying children into only two groups may be another source of error given evidence that there may be more than two language ability groups with different strengths and weaknesses or, alternatively, a single group characterized by a continuum of language performance. The current study tested for the number of distinct language ability groups and their characteristics in predominately Spanish-speaking children in the U.S. without using an a priori classification as a reference. In addition, the study examined to what extent the latent groups differed on each measure, and the stability of language ability groups across three assessment methods in Spanish (standardized tests, language sample analyses, and comprehensive assessment), taking in to account English and non-verbal cognitive skills. The study included 431 bilingual children attending English-only education. Three latent profile analyses were conducted, one for each method of assessment. Results suggested more than two distinct language ability groups in the population with the method of assessment influencing the number and characteristics of the groups. Specifically, four groups were estimated based on the comprehensive assessment, and three based on standardized assessment or language sample analysis in Spanish. The stability of the groups was high on average, particularly between the comprehensive assessment and the standardized measures. Results indicate that an a priori classification of children into two groups, those with and without PLI, could lead to misclassification, depending on the measures used.
ContributorsKapantzoglou, Maria (Author) / Restrepo, Maria A. (Thesis advisor) / Gray, Shelley S. (Committee member) / Thompson, Marilyn S. (Committee member) / Arizona State University (Publisher)
Created2012
Description
Identification of primary language impairment (PLI) in sequential bilingual children is challenging because of the interaction between PLI and second language (L2) proficiency. An important step in improving the accurate diagnosis of PLI in bilingual children is to investigate how differences in L2 performance are affected by a length of L2 exposure and how L2 assessment contributes to differentiation between children with and without PLI at different L2 proficiency levels. Sixty one children with typical language development (TD) ages 5;3-8 years and 12 children with PLI ages 5;5-7;8 years participated. Results revealed that bilingual children with and without PLI, who had between 1 and 3 years of L2 exposure, did not differ in mean length of utterance (MLU), number of different words, percent of maze words, and performance on expressive and receptive grammatical tasks in L2. Performance on a grammaticality judgment task by children with and without PLI demonstrated the largest effect size, indicating that it may potentially contribute to identification of PLI in bilingual populations. In addition, children with PLI did not demonstrate any association between the length of exposure and L2 proficiency, suggesting that they do not develop their L2 proficiency in relation to length of exposure in the same manner as children with TD. Results also indicated that comprehension of grammatical structures and expressive grammatical task in L2 may contribute to differentiation between the language ability groups at the low and intermediate-high proficiency levels. The discriminant analysis with the entire sample of bilingual children with and without PLI revealed that among L2 measures, only MLU contributed to the discrimination between the language ability groups. However, poor classification accuracy suggested that MLU alone is not a sufficient predictor of PLI. There were significant differences among L2 proficiency levels in children with TD in MLU, number of different words, and performance on the expressive and receptive grammatical tasks in L2, indicating that L2 proficiency level may potentially impact the differentiation between language difficulties due to typical L2 acquisition processes and PLI.
ContributorsSmyk, Ekaterina (Author) / Restrepo, Maria Adelaida (Thesis advisor) / Gorin, Joanna (Committee member) / Gray, Shelley (Committee member) / Arizona State University (Publisher)
Created2012