The data come from a study in which 30 female rats were randomly assigned to receive one of three doses (High, Low, or Control) of an experimental compound.
A data frame with 322 observations on the following 6 variables.
: Unique identifier for each rat pup
: Birth weight of the rat pup (the dependent variable)
: Sex of the rat pup (Male, Female)
: Litter ID number
: Litter size (i.e., number of pups per litter)
: Dose level of the experimental compound assigned to the litter (High, Low, Control)
Pinheiro, J.C. and Bates, D.M., Mixed-effects models in S and S-PLUS, Springer-Verlag Inc., Berlin, New York, 2000.
West, B., Welch, K. & Galecki, A, Linear Mixed Models: A Practical Guide Using Statistical Software, Chapman Hall / CRC Press, first edition, 2006.