  Phase II dose finding studies in clinical drug development are typically
conducted to adequately characterize the dose response relationship of a new
drug. An important decision is then on the choice of a suitable dose response
function to support dose selection for the subsequent Phase III studies. In
this paper we compare different approaches for model selection and model
averaging using mathematical properties as well as simulations. Accordingly, we
review and illustrate asymptotic properties of model selection criteria and
investigate their behavior when changing the sample size but keeping the effect
size constant. In a large scale simulation study we investigate how the various
approaches perform in realistically chosen settings. Finally, the different
methods are illustrated with a recently conducted Phase II dosefinding study in
patients with chronic obstructive pulmonary disease.
