A small toxological experiment data.
The subjects are fetuses from
two randomized groups of pregnant rats,
and they were given a placebo or chemical treatment.
The number with birth defects were recorded, as well
as each litter size.
Usage
data(prats)
Arguments
Format
A data frame with the following variables.
treatment
A 0 means control;
a 1 means the chemical treatment.
alive, litter.size
The number of fetuses alive at 21 days, out of
the number of fetuses alive at 4 days (the litter size).
Details
The data concerns a toxological experiment where
the subjects are fetuses from
two randomized groups of 16 pregnant rats each,
and they were given a placebo or chemical treatment.
The number with birth defects and the litter size were recorded.
Half the rats were fed a control diet during pregnancy and
lactation, and the diet of the other half was treated with a
chemical. For each litter the number of pups alive at 4 days
and the number of pups that survived the 21 day lactation period,
were recorded.
References
Williams, D. A. (1975).
The Analysis of Binary Responses From Toxicological
Experiments Involving Reproduction and Teratogenicity.
Biometrics,
31(4), 949--952.