To This is a 1 test per thousand learn more about normal language development in deaf children, we have developed the MacArthur Communicative Development Inventory for American Sign Language (ASL-CDI), a parent report that measures early sign production. The ASL-CDI is an inventory of sign glosses organized into semantic categories targeted to assess sign language skills in children ages 8 to 36 months. The ASL-CDI uses a recognition format in which parents check off signs that their child produces. The form has demonstrated excellent reliability and validity. To date, normative data have been collected from 69 deaf children with deaf parents who are learning sign language as a first language. We discuss the development of the ASl-CDI and preliminary cross-sectional and longitudinal findings from this early data collection with particular focus on parallels with spoken language acquisition. We also discuss the acquisition of first signs, negation, wh-questions, and fingerspelling with developmental patterns provided based on age, as well as vocabulary size.
