On group sequential tests based on robust location and scale estimators in the two-sample problem
نویسنده
چکیده
The behaviour of group sequential tests in the two-sample problem is investigated if one replaces the classical non-robust estimators in the t-test statistic by modern robust estimators of location and scale. Hampel's 3-part redescending M-estimator 25A used in the Princeton study and the robust scale estimators length of the shortest half proposed by Rousseeuw & Leroy and Q proposed by Rousseeuw & Croux are considered. Of special interest are level, power and the average sample size number of the tests. It is investigated , whether commerical software can be used to apply these tests.
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