Abstract
This study investigated the diagnostic accuracy of various dynamic assessment (DA) protocols in identifying Developmental Language Disorder (DLD) among English-Spanish bilingual preschoolers. Traditional static assessments often misclassify DLD in bilingual children due to their inherent bias towards monolingual norms, leading to both over- and under-identification. We hypothesized that DA, which evaluates learning potential rather than just current knowledge, would offer superior diagnostic precision. A cohort of 85 English-Spanish bilingual preschoolers (aged 4-5 years), comprising children with DLD and typically developing (TD) peers, participated. Three distinct DA protocols focusing on vocabulary, grammar, and narrative skills were administered, alongside a comprehensive battery of static measures and expert clinical diagnoses serving as the gold standard. Results indicated that the DA protocols, particularly those integrating mediated learning experiences and a test-teach-retest paradigm, demonstrated significantly higher sensitivity and specificity for DLD identification compared to static assessments. The DA protocols effectively distinguished DLD from typical second language acquisition challenges, minimizing misclassification errors. These findings underscore the critical role of dynamic assessment in providing equitable and accurate DLD diagnoses for bilingual populations, promoting timely intervention and support.