Word frequencies in toddlers' lexicons.

Word frequencies in toddlers' lexicons were examined in two studies using the Language Development Survey (LDS), a vocabulary checklist completed by parents (Rescorla, 1989). In Study 1, a high degree of consistency in LDS word frequencies was found when six samples of 24-month-olds were compared (total N = 758). Word frequency correlations in the .90s were found between large, unselected samples of toddlers of roughly similar socioeconomic status (SES). Correlations were somewhat lower but still highly significant when groups varying widely in SES were compared. In Study 2, LDS word frequencies in a sample of 40 late talkers traced from age 2 to 3 were compared to those in a large community sample from Study 1. Both lexicon size and age of the late talker influenced the degree of consistency found with respect to the community sample. The most common words reported in the lexicons of a sample of 422 24-month-olds were consistent with those identified in diary studies as among the highest frequency words used by young children in their early vocabularies.