The Informative Analysis of Individual Trend Curves

Additive and non-additive models for an individual trend curve are examined, and five methods for fitting these to a set of individuals are described. It is suggested that classical fitting methods are more informative than latent curve methods, and commonly preferable. A limited study of the effect of time-structure is reported, and results on the relationship between a non-additive model and the approximating additive model are given.