AbstractBilingual children are often misdiagnosed as having a speech disorder when they truly exhibitnormal development. In addition speech-language pathologists (SLP) are avoiding theassessment of bilingual children due to the lack of knowledge and resources necessary for bestpractice with this population. Misdiagnosis of speech sound disorders in this population haslong-term emotional financial and educational costs. Misdiagnosis of speech disorders inbilingual children can be prevented if we acquire more information on what constitutes normaland disordered speech development in the bilingual population. The current research isdesigned to validate a model of speech sound production in bilinguals to frame a screening toolfor Latino preschoolers. Due to differences in speech production found in bilingual preschoolers(Fabiano-Smith & Goldstein 2010a; 2010b; Fabiano-Smith & Barlow 2010) an assessmentprocedure that evaluates the speech of bilingual preschoolers that takes into account bothEnglish and Spanish is necessary to prevent misdiagnosis of speech sound disorders. TheSpecific Aims of the proposed research are to (1) to validate our model of speech soundproduction in bilinguals the PRIMIR 2 model and (2) to improve the existing version of theassessment procedure utilized in Phase 1 of our research using Item Response and ClassicalTest Theory approaches to reliability. Bilingual children with typical and disordered developmentwill be compared to their English-speaking peers on measures of speech sound ability. Childrenwill produce sounds in single words and their productions will be phonetically transcribed. Childproductions will be examined in both English and Spanish and across both languages oncommon diagnostic measures used for monolingual children. Mixed effects regression modelswill be used to identify between-language interaction in bilingual speech and the ReceiverOperating Characteristic Curve (ROC) will be used to determine sensitivity and specificity of thediagnostic measures examined. Item Response Theory (IRT) will be used to identify a set of testitems that are sensitive and specific to bilingual children with suspected speech sounddisorders. Findings will lead to a characterization of typical and disordered speech sounddevelopment in bilingual children and diagnostic guidelines for speech-language pathologists touse in the differential diagnosis of speech difference from speech disorder. These findings willreduce diagnostic error in the identification of speech sound disorders in this populationreducing health disparities for Latino children.