Turn-taking and overlap in the speech of young Down's syndrome children

This study has examined incidents involving vocal overlap in recordings made in the homes of four 3-year-old Down's children. Previous research has suggested a higher incidence of vocal clashes and interruptions in the interaction of Down's children than in that of non-handicapped children. In our data, the overall incidence of overlaps initiated by the child was higher for the two less advanced children. However, such overlaps do not necessarily indicate poor turn-taking coordination; slight overlaps, and overlaps which occur close to where a speaker had reached a potential completion point in their turn, need to be distinguished from those which begin in the middle of turn-constructional units. The children's behaviour when overlap occurred was also examined. A number of techniques which show a child's awareness of the fact that overlap has occurred were identified. By using overlap-sensitive techniques, a child is treating overlap as a problem to be remedied. While the most advanced child used six such techniques, there was not clear evidence of the least advanced child using any of them.