A line of reasoning used in recent research on language acquisition assumes that a child acquiring the language has only two reliable sources of information available about the target grammar: a set of grammatical principles and the primary data of the language spoken around him. A third kind of evidence, negative evidence, would be helpful but is…

This review of research discusses how children with autism may acquire equivalence classes after learning to supply a common oral name to each stimulus in a potential class. A proposed methodology for researching referent naming and class formation, analysis of stimulus classes, and generalization is offered. (CR)

Presents methodological and factual analyses of children's use of imitative speech as a strategy in language acquisition. The impact of conversational interactions and picture-story books on the speech of one girl aged 20 to 32 months is demonstrated. Four methodological problem areas are analyzed. (Author/RH)