Sökning: "Marie-Louise Öhman"
Hittade 2 avhandlingar innehållade orden Marie-Louise Öhman.
1. Aspects of analysis of small-sample right censored data using generalized Wilcoxon rank tests
Sammanfattning : The estimated bias and variance of commonly applied and jackknife variance estimators and observed significance level and power of standardised generalized Wilcoxon linear rank sum test statistics and tests, respectively, of Gehan and Prentice are compared in a Monte Carlo simulation study. The variance estimators are the permutational-, the conditional permutational- and the jackknife variance estimators of the test statistic of Gehan, and the asymptotic- and the jackknife variance estimators of the test statistic of Prentice. LÄS MER
2. Contributions to generalized Wilcoxon rank tests
Sammanfattning : In unbalanced small sample size problems with right censorings, the variance estmators of linear rank statistics, may be biased. This is the case with the commonly applied variance estimators for the generalized Wilcoxon rank test statistics of Gehan and Prentice. LÄS MER