Using parent report to assess bilingual vocabulary acquisition: a model from Irish

This chapter describes the adaptation of a parent report instrument on early language development to a bilingual context. Beginning with general issues of adapting tests to any language, particular attention is placed on the issue of using parents as evaluators of child language acquisition of a minority language in a bilingual context. In Ireland, Irish is the first official language and is spoken by about 65,000 people on a daily basis. However all Irish speakers are bilingual, and children are exposed to the dominant English language at an early age. Using an adaptation of a parent report instrument, 21 typically developing children between 16 and 40 months were assessed repeatedly over two years to monitor their language development. The form allowed parents to document their children’s vocabulary development in both languages. Results showed that when knowledge of both languages was accounted for, the children acquired vocabulary at rates similar to those of monolingual speakers and used translational equivalents relatively early in language development. The study also showed that parents of bilingual children could accurately identify and differentiate language development in both of the child’s languages. Recommendations for adapting and using parent report instruments in bilingual language acquisition contexts are outlined.