Total and conceptual vocabulary in Spanish-English bilinguals from 22 to 30 months: implications for assessment.

Abstract

Vocabulary assessment holds promise as a way to identify young bilingual children at risk for language delay. This study compares 2 measures of vocabulary in a group of young Spanish-English bilingual children to a single-language measure used with monolingual children. Total vocabulary and conceptual vocabulary were used to measure mean vocabulary size and growth in 47 Spanish-English bilingually developing children from 22 to 30 months of age based on results from the MacArthur-Bates Communicative Development Inventory (CDI; Fenson et al., 1993) and the Inventario del Desarrollo de Habilidades Comunicativas ( Jackson-Maldonado et al., 2003). Bilingual children's scores of total vocabulary and conceptual vocabulary were compared with CDI scores for a control group of 56 monolingual children. The total vocabulary measure resulted in mean vocabulary scores and average rate of growth similar to monolingual growth, whereas conceptual vocabulary scores were significantly smaller and grew at a slower rate than total vocabulary scores. Total vocabulary identified the same proportion of bilingual children below the 25th percentile on monolingual norms as the CDI did for monolingual children. These results support the use of total vocabulary as a means of assessing early language development in young bilingual Spanish-English speaking children.