Early | R Documentation |
Cognitive scores of infants in a study of early childhood intervention. The 103 infants from low income African American families were divided into a treatment group (58 infants) and a control group (45 infants). Starting at 0.5 years of age the infants in the treatment group were exposed to an enriched environment. Each infant's cognitive score on an age-specific, normalized scale was recorded at ages 1, 1.5, and 2 years.
data(Early)
This groupedData
object contains the following columns
An ordered factor of the id number for each infant.
A numeric cognitive score.
The age of the infant at the measurement.
A factor with two levels, "N"
and "Y"
,
indicating if the infant is in the early childhood intervention
program.
Singer, Judith D. and Willett, John B. (2003), Applied Longitudinal Data Analysis, Oxford University Press. (Ch. 3)
str(Early)