Abstract
Nonparametric methods are developed for estimating the dose effect when a response consists of correlated observations over time measured in a dose–response experiment. The methods can also be applied to data collected from a completely randomized design experiment. Methods are developed for the detection and description of the effects of dose, time, and their interaction. The methods allow for individual variation in the timing and number of observations. A generalization allowing baseline covariates to be incorporated is addressed. These results may be used in an exploratory fashion in the process of building a random-effects model for longitudinal data.