0 Ablex Publishing Corp. Early Childhood Research Quarterly, 12, 59-79 (1997) ISSN 0885-2006 The Role of Private Speech in the Transition From Collaborative to independent Task Performance in Young Children Adam Winder George Mason University Rafael M. Diaz University of California, San Francisco lgnacio Montero Universidad Auttkoma de Madrid This study was designed to examine the following central Vygotskian hypotheses about the functions of preschool children’s private speech: (1) that private speech facilitates the transition from collaborative to independent task performance, and (2) that children’s use of private speech is conducive to task success. Age-related changes in children’s use of private speech were also examined. Forty preschool- ers, ranging in age from three to five, completed a selective attention task with scaffolded assistance given from an experimenter when needed. In an effort to overcome several methodological limitations found in previous research, a new microgenetic method of analyzing speech-performance relations based on assign- ing task items to discrete categories reflecting six possible co-occurrences between private speech (item-relevant speech, item-irrelevant speech, silence) and performance (success, failure) was introduced. Results were that (1) item-rel- evant speech was used more often during successful than during failed items while the opposite was true for item-irrelevant speech; (2) children were more likely to use private speech on successful items after scaffolding than they were on similar items not following scaffolding; (3) after scaffolding, children were more likely to succeed on the next item if they talked to themselves than if they were silent; and (4) hypothesized curvilinear, age-related patterns in children’s item-relevant private speech and silence were found, however, only when analyz- ing speech during successful items. Implications of this research for preschool teachers and parents are discussed. One of Vygotsky’s (1934/1962, 1930-1935/1978, 1960/1981) most intriguing observations was that young children use language not only for social communi- cation but also to plan, guide, and monitor their behavior in a self-regulatory man- ner. The use of language for self-regulation is labeled private speech, underscoring the fact that it is different from social speech in both audience (self, rather than others) and function (self-regulation, rather than social communica- Direct all correspondence to: Adam Winsler, Department of Psychology-3FS, George Mason Univer- sity, Fairfax, VA 22030. E-mail: awinsler@gmu.edu 59