A quantitative analysis of the single-word stage

A quantitative analysis of the single-word stage was performed by evaluating children's production of words, relative to nonwords, along a monthly developmental continuum. The vocalizations of six children were sampled over a period of one year, spanning the first two years of life. The development of word use was studied by calculating the ratio of words to nonwords in each child's monthly vocalization sample. Results of the analyses indicated that nonwords were present in the children's vocalizations throughout the single-word stage of development. Further, individual children had distinct ‘word curves’ defining their early lexical development. The resulting word curves are discussed in the context of stage models of vocalization development and existing measures of speech and language acquisition.