The research reported here focuses on one aspect of the communicative environment, namely vocabulary. The central question motivating this research was whether there are social class and ethnic group differences in the vocabulary used in the home and in the school situation. A corpus of talk was searched for the use of words from four standardized intelligence tests: Stanford-Binet, WISC-R, WPPSI, and Peabody. The number of different words that speakers used in the home and in the school situations was the dependent variable. Subjects were 36 children, aged 4 1/2 to 5 years, and their teachers and parents. Race and social class were the independent variables. Results showed that the school communicative environments of children from different social class and ethnic backgrounds did not differ in any significant way. The home communicative environments did differ along social class lines. (Author/TJ)