THE INITIAL GROWTH OF EXPRESSIVE VOCABULARY AMONG CHILDREN WITH DOWN-SYNDROME

Longitudinal data on the unstructured interactions at home of 9 childr en with Down syndrome were used to compare individual differences in i nitial expressive vocabulary growth to group data identically collecte d longitudinally on children without disabilities. The overall pattern of vocabulary growth was similar in all the children. Among the child ren with Down syndrome, differences in initial learning strategies, an asynchrony between growth of vocabulary and MLU, and differences betw een individual children of as long as 2 years in producing the first 5 0 words of expressive vocabulary were seen. Implications for intervent ion are discussed.