At the 3-year laboratory visit, children were administered the Peabody Picture Vocabulary Test-III (PPVT; Dunn & Dunn, 1997), a standardized assessment of receptive language ability. The experimenter kept track of the child’s accuracy as the task was administered; trained research assistants later scored the task according to the procedures in the manual. Specifically, the raw score was calculated by subtracting the number of errors from the ceiling item; higher scores indicate a larger receptive vocabulary. Twenty-two children were not administered this task because they did not participate in the 3-year lab visit; 6 were not administered the task because it was not in the protocol; 4 could not be scored because a basal set could not be established (i.e., they missed more than 2 on the first set).
