We consider repeated observations taken over time for each of several subje
cts. For example, one might consider the growth curve of a cohort of babies
over time. We assume a simple linear growth curve model. Exact results bas
ed on sufficient statistics (exact tests of the null hypothesis that a coef
ficient is zero, or exact confidence intervals for coefficients) are not av
ailable to make inference on regression coefficients when an intraclass cor
relation structure is assumed. This paper will demonstrate that such exact
inference is possible using generalized inference.