Sources of support for learning words in conversation: evidence from mealtimes.

This study examines mealtimes of preschoolers' families to determine whether rare words are used in informative ways so that a child could learn their meanings. Is there an association between informative use of rare words and the child's later vocabulary? Each use of rare words in 160 transcripts was coded for whether it was informative or uninformative. Each informative exchange was coded for type of strategy used to provide support: physical or social context, prior knowledge, and semantic support. There were 1,631 exchanges around rare words. About two-thirds of these exchanges were informative uses from which the child could learn the word's meaning. The most frequent strategy used was semantic support, accounting for two-thirds of strategies used. The frequency of use of rare words was positively correlated with age-five and age-seven PPVT scores.