Hartung, Joachim2004-12-062004-12-062000http://hdl.handle.net/2003/501610.17877/DE290R-5526For testing one{sided but also two{sided hypotheses concerning several treatment arms in group sequentially performed clinical trials with arbitrary outcome variables, a general learning method is considered that allows for a complete self-designing of the study. All information available prior to a stage is used for estimating the sample size and the weight for the next step. In 'using up' the variance, the test statistic is built in a bounded finite but random number of stages toenUniversitätsbibliothek Dortmund310report