Innovations in Conceptual Scoring of a Bilingual Expressive Vocabulary Measure.

Purpose: Conceptual scoring is a useful approach to bilingual vocabulary tests that can identify language delays or impairments by considering bilingual children's lexical-semantic knowledge in both languages. The purpose of this study was to develop and calibrate a conceptually scored expressive vocabulary measure, the Multitudes Expressive Vocabulary (EVO) task, for use in screening Spanish-English bilingual children.

Method: Item design of the English and Spanish items was informed by prior literature and bilingual corpus data, and item review was conducted to ensure linguistic appropriateness and to minimize racial or cultural bias in English and Spanish versions. To begin item calibration in each language, English and Spanish items were administered to the same 1,219 bilingual children enrolled in kindergarten and first grade. Item-level difficulties were calculated using Rasch modeling in each language and then were correlated across languages.

Results: Correlations met minimum thresholds, which justified joint calibration on a unitary scale, and there was evidence of unidimensionality. The conceptually scored version had appropriate item fit statistics across the range of ability. Finally, moderately positive correlations with an existing measure of bilingual expressive vocabulary provided evidence of criterion validity.

Conclusions: The development process of the Multitudes conceptually scored expressive vocabulary screening measure is described. A final set of empirically derived items had appropriate fit statistics and had evidence of construct validity when conceptually scored. Multitudes EVO represents an innovation in universal screening by allowing students to respond in English or Spanish, which improves accuracy and efficiency.