Using a monolingual screening test for assessing bilingual children.

Bilingual language development is different from monolingual language development. The lack of appropriate assessment tools geared to the bilingual population has led to inaccurate over-diagnosis of bilingual children with typical language development (TLD) as children with Developmental Language Disorder (DLD) and under-diagnosis of bilingual children with DLD. The present paper addresses this challenge by focusing on Hebrew as a second language (L2) of bilingual preschool children whose first language (L1) is either English or Russian, taking into consideration both chronological age (CA) and age of onset of bilingualism (AOB). This study aimed to generate bilingual standards for a monolingual screening test, by arriving at appropriate bilingual typical development cut-off points. A total of 443 bilingual Hebrew speaking children (397 with TLD and 46 with DLD), ages 61-78 months ( = 70;  = 4), 199 with L1 English and 244 with L1 Russian, took part in the study. The results demonstrate low diagnostic accuracy when a monolingual test with monolingual norms is used for bilingual children, in contrast with increased diagnostic accuracy when bilingual standards are used for bilingual children. The paper concludes by showing the importance of bilingual standards when assessing clinical populations with varying ages of acquisition, and in particular, for those who were exposed to their second language after the age of four.