Optimizing a Vietnamese Sentence Repetition Task Using Item Response Theory.

Purpose: Sentence repetition can contribute to the identification of developmental language disorder (DLD). However, few studies have attempted to optimize the task for clinical practice. This study uses the item response theory (IRT) to optimize a Vietnamese sentence repetition task for screening and full-assessment purposes and evaluate the diagnostic utility of the new item sets.

Method: We expanded the original task from 28 to 40 items to maximize the chances of having robust final item sets. The 40 items were administered to 196 children in Vietnam, ages 4-6 years. Participants met criteria for DLD (n = 28) or typical development (n = 122), while a subset did not meet criteria for either classification (i.e., Risk, n = 46). Using IRT, we compared different scoring systems and selected item sets with robust parameters and adequate fit to serve two clinical purposes, assessment and screening. We calculated diagnostic accuracy of these item sets using discriminant function analysis and compared results to raw score cut-points.

Results: The optimal item set for full assessment included 28 items (15 original items) and showed strong diagnostic accuracy, as did a 14-item subset (seven original items) designed for screening. The item set for full assessment also provided a quick characterization of children's grammatical performance. The strongest diagnostic values were derived from discriminant function analysis.

Conclusions: This study optimized two sentence repetition tasks for monolingual Vietnamese children for use in a full assessment or screening. Implications are discussed on how to utilize tasks in clinical practice. Future studies need to evaluate sentence repetition in older children and bilingual populations.

Supplemental material: https://doi.org/10.23641/asha.28570475.