ABSTRACT
Students of language development have reached an important new consensus. The hypothesized dependency of language upon cognition might liberate the study of language development from one of its chief anchors, which is that poorly formed or grammatically incomplete utterances are open to multiple interpretations. The student of language development has to resolve the ambiguities in order to draw conclusions about the nature of language development. The foregoing work on infants' perception of speech illustrates that it can be heuristic to use our understanding of language to generate research about perceptual and cognitive development. The study of the development of segmentation and discrimination has been severely constrained by the authors’ ignornace of the functional units of speech. Normal language development proceeds at such a rapid pace, and on so many fronts at once, that they undoubtedly miss many of its elements and their interactions when they study only normal children.
