Showing 1 - 10 of 53
A class of self-designing clinical trials is considered which according to an effective but simple, finite learning algorithm consists of automatically adaptively planned weighted group sequential trials with a decision about rejection of the null-hypothesis at each step, but the full...
Persistent link: https://www.econbiz.de/10009787273
In a general variance component model with positive variance components a short-cut method is presented that yields almost everywhere for these components positive estimators that are invariant with respect to mean value translation and stay near the unbiasedness.
Persistent link: https://www.econbiz.de/10009792341
In combining several tests of significance the individual test statistics are allowed to be dependent. By choosing the weighted inverse normal method for the combination, the dependency of the original test statistics is then characterized by a correlation of the transformed statistics. For this...
Persistent link: https://www.econbiz.de/10010431896
In many fields of applications, test statistics are obtained by combining estimates from several experiments, studies or centres of a multicentre trial. The commonly used test procedure to judge the evidence of a common overall effect can result in a considerable overestimation of the...
Persistent link: https://www.econbiz.de/10010438776
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Persistent link: https://www.econbiz.de/10003780938
Research in combining of economic forecasts made by several research institutes on the same economic variable has focused on estimation, hoping that the combined forecast will be improved by taking into account the expert opinions of the institutes. We provide a confidence interval on the...
Persistent link: https://www.econbiz.de/10009772049
In this paper we derive asymptotic x 2 - tests for general linear hypotheses on variance components using repeated variance components models. In two examples, the two-way nested classification model and the two-way crossed classification model with interaction, we explicitly investigate the...
Persistent link: https://www.econbiz.de/10009783545
Different estimation methods for covariance parameters in meta-analyses can result in conflicting p-values concerning the test of treatment effect. We propose a valid method to overcome this problem at least partially by introducing a new estimator for the standard deviation of the common...
Persistent link: https://www.econbiz.de/10009787269
Concerning the actual significance level, we investigate the commonly used combined test procedures of meta-analysis, which contain the choice of the model, in which the analysis is carried out, and the commonly used tests for treatment effect in the fixed and random effects model, and some new...
Persistent link: https://www.econbiz.de/10009787270