Young children were found to overextend and underextend newly uttered but previously understood words. The data are discussed in terms of differences between children's and adult's word meanings and between comprehension and production. (Author)

To understand the development of number-word construction, students in grades 1, 3, 5, and 7 named and counted from a set of numbers into the billions in two studies. Findings are discussed both in relation to children's growing knowledge of the number system and to vocabulary development. (Author)

This report describes an investigation of the acquisition by children of a symbolic system, specifically English nomenclature--that set of nouns that serves the function of naming, denoting, or referring to objects. The five studies involve nine experiments dealing with one or another of the aspects of this problem. Two questions guided these…