Three experimental tasks explored young children's metalinguistic awareness of word boundaries. First, preschool children recited word-by-word pieces which differed in abstractness and familiarity of vocabulary. Second, a teaching task was employed to train and then sample selected items taken from the recited pieces, representing words with cards. The data suggested that several strategies were employed: segment-by-phrase, segment-by-syllable, and segment-by-word. Children were less successful in segmenting the more abstract piece than the concrete one, and they tended to revert to a phrase strategy and/or to change abstract words into more common vocabulary. Error analysis revealed growing awareness of the functors a and the. In a third experiment, preschool and kindergarten children segmented phrases using the functors a, an, my, or and phrases using phonetically similar embedded syllables (e.g., hold my nose; gold miner). Segmentation scores increased with age; even the 4½- to 5-year-olds were highly successful, segmenting with 60% accuracy, and by age 6–6½, they were correctly segmenting 75% of the phrases. Children who had begun to read performed better overall than their same-age peers who had not. Children were more successful with my, or, and word-medial a than with an and word-initial a; embedded syllables tended to be easier than functors, especially for the younger subjects. In conclusion, the years from age 4½- to 6½ appear to be a period of vigorous development of word segmentation skills. During this period, children use increasingly complex strategies – first phrasal, then syllabic, and finally a full word strategy – and they demonstrate a growing knowledge of function words as well as content words. Functors vary in difficulty and developmental sequence due to differences in stress, amount of ambiguity with phonetically similar embedded syllables, semantic complexity, and salience of reference to the young child.

Preschool children's early understanding of letters was explored using literacy events focusing on name. Five tasks were designed to elicit information about children's conceptualizations of letters in their own names. Responses were analyzed descriptively to determine general patterns. Children were then clustered into strategy groups. These groups provided a basis for a developmental description. Children's own names proved to be a unique source for creating and testing hypotheses concerning letters due to frequent exposure to both the printed script and the oral script (the spelling of name). This exploration was marked by several major transitions: a movement from a unidimensional conceptualization of letters to a multidimensional conceptualization; a movement from general principles to an assimilation of specific knowledge regarding the principles; and a movement from independent explorations of the printed and oral scripts to integration of the two scripts.

This study investigated the ability of high-functioning verbal adolescents with autism or Down's syndrome to perform a referential communication task. It was predicted that autistic subjects would require more specific prompting to convey needed information to a listener than would subjects with Down's syndrome of the same verbal level. Subjects, 13 with autism and 14 with Down's syndrome, matched on verbal mental age, learned a simple board game, and were asked to teach it to a listener who used varying levels of prompting to elicit target information. Most subjects in the autistic group required specific prompting to produce the target information, whereas most subjects with Down's syndrome did not. Response adequacy was significantly higher in the Down's syndrome group than in the autistic group at the most general prompt level. Subjects with Down's syndrome used more gesture at the most general prompt level and when producing high adequacy responses, whereas subjects with autism used more gesture when producing low adequacy responses.

In order to assess the effect of total deafness on vocalization development, tape recorded utterances of a 3-year-old child who was born without cochleas were examined. In the beginning of the study, the subject's speech consisted almost exclusively of small numbers of sounds characteristic of early infancy. Across the study, the subject participated in extensive vocal stimulation activities. He also initially received intermittent exposure to tactile speech information via a 16-channel vocoder and, subsequently, a 2-channel tactile aid. Following introduction of the 2-channel aid, the subject made rapid improvement in the quality of his vocalizations, which consisted increasingly of speech-like utterances, including well-formed or canonical syllables. These results suggest that, although hearing impairment slows the onset of canonical babbling, even total deafness does not preclude its eventual appearance.

Child first-language (L1) learners frequently use the definite article in referential indefinite contexts, that is, with nouns appearing in the discourse for the first time, where adults use the indefinite article. Adult second-language (L2) learners also overgeneralize the definite article. Research reported here shows 30 L2 learners use the in referential indefinite contexts at significantly higher rates than in nonreferential contexts. Thus, both L1 and L2 learners may share an initial hypothesis associating the with referential nouns. This evidence of a strategy common to L1 and L2 learners invites reinterpretation of both L1 and L2 acquisition data.

The method of sorting is used to compare sets of adjectival contexts. Contexts of directly antonymous adjectives are found to be highly discriminable, both with sentential and phrasal contexts. These results are used to argue that words with different meanings normally appear in discriminably different contexts, and that the cue for learning to associate direct antonyms is not their substitutability, but rather their relatively frequent co-occurrence in the same sentence.