The abstracts are given below. A clinical trial model is considered in which two treatments with immediate binary responses are to be compared. An adaptive urn design is used to assign patients to the treatments. The bias and variance of the maximum likelihood estimators of the probabilities of success are derived by differentiating the fundamental identity of sequential analysis. By embedding the design in a continuous-time process, probability generating functions are then calculated to obtain approximations for the bias and variance.
Simulation is used to assess the accuracy of the approximations.
Methods for correcting for bias are also addressed. S. Ghosh, pp. In Adaptive Designs , eds. N. Flournoy and W.F. Rosenberger, pp. Book Reviews Review of Asymptotic Statistics by A.W. van der Vaart.