Elizabeth Bates (1947-2003)
Department of Psychology
University of California San Diego
|Type of Study:||all children at 10, 13, 20, and 28 months|
Bates, E., Bretherton, I., & Snyder, L. (1988). From first words to grammar: Individual differences and dissociable mechanisms. Cambridge, MA: Cambridge University Press.
Carlson-Luden, V. (1979). Causal understanding in the 10-month-old. Unpublished doc-toral dissertation. University of Colorado at Boulder.
In accordance with TalkBank rules, any use of data from this corpus must be accompanied by at least one of the above references.
This corpus contains transcripts from the Bates/Bretherton Colorado longitudinal sample of middle-class children studied in Boulder, Colorado, between 1978 and 1980. There are four subdirectories: free20, free28, snack28, and story28. These names indicate the ages of the children in months and the nature of the activity in which they were engaged. Children were studied at four age levels: 10, 13, 20, and 28 months. The initial sample included 32 children, but only 27 participated at all four ages. At each age level, data were collected in two sessions. The first session was always held in the home, followed by a session in the laboratory no more than 7 days later. Detailed transcriptions are available only for the laboratory session. At 20 months, there are only transcripts of motherese sequence of structured procedures that followed. The three situations include: free play with the same instructions and the same toys used in the 20-month segment, reading of the book Miffy in the Snow, and a snack.
The children were all originally participants in a study of causal understanding in infancy (Carlson-Luden, 1979) involving an initial group of 48 infants with an average age of 0;10.11 (with a range from 0;10.0 to 0;10.28). At the end of the Carlson-Luden study, par-ents were asked if they would be willing to participate in our longitudinal study of language and symbolic development, up through 28 months of age. The parents of 32 children agreed, resulting in a starting sample of 16 boys and 16 girls. These infants were next seen at 13 months of age. Five children subsequently moved away. At 20 months, three new children were therefore invited to participate in the project, to bring the sample up to 15 boys and 15 girls. This sample of 30 children all participated in the final sessions at 28 months. Although the total sample varied from one session to another, 27 children participated at all four age levels. All the analyses in Bates, Bretherton, and Snyder (1988) are based on this constant sample of 27, including 13 boys and 14 girls. Thirteen children were first-born, 10 were second-born, and 4 were third-born or later. Their average birthweight was 7.2 pounds, with a range from 5.5 to 9.0 lbs. Average age in days at the initial 10-month session was 311, with a range from 300 to 324. At all subsequent sessions, children were within 2 weeks on either side of the target range.
A note regarding the demographic make-up of this sample: Although we did not select participants systematically on the basis of race or socioeconomic level, the demographic characteristics of Boulder, Colorado are such that these selection criteria resulted in a sam-ple of middle- to upper-middle-class White children (with the exception of one Black child from a middle-class family). This was, then, a very homogeneous and privileged group of children, a fact that of course limits the generalizability of our findings to other groups.