Method
Participants
Twelve nursery classes were selected for the intervention, two
from each of six privately-owned day care nurseries in Berkshire.
Six classes included 12- to 24-month-old children, while six classes
included 24- to 36-month-old children. Three classes from each age
group were randomly assigned to form the experimental group; the
remaining three classes comprised the control group. A total of 121
children were recruited, of whom 92 completed the test session,
55 in the experimental condition (mean age = 2; 0, range = 1; 1–2;
11) and 37 in the control group (mean age = 2; 0, range = 1; 0–2;
9). The remaining 29 children were absent on the day of testing,
largely due to family holidays. Informed consent was provided by
the parents of all participants.