Sökning: "Censored data rank sum tests"

Hittade 2 avhandlingar innehållade orden Censored data rank sum tests.

  1. 1. Contributions to generalized Wilcoxon rank tests

    Författare :Marie-Louise Öhman; Hans Nyquist; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Censored data rank sum tests; Gehan s test; Generalized Wilcoxon test; Jackknifing; Two sample problem; Simulation; Survival data; Variance estimation; Influence function; Gross error sensitivity; Sensitivity curve; Misclassification; Statistics; computer and systems science; Statistik; data- och systemvetenskap; Statistics; statistik;

    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

  3. 2. Aspects of analysis of small-sample right censored data using generalized Wilcoxon rank tests

    Författare :Marie-Louise Öhman; Hans Nyquist; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Censored generalized Wilcoxon rank test statistics; Variance estimation; Jackknifing; Influence function; Gross error sensitivity; Break-Down point; Sensitivity curve; Location parameter estimation; Product-Limit estimator and Monte-Carlo Simulation; Statistics; computer and systems science; Statistik; data- och systemvetenskap; Statistics; statistik;

    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