The Wilcoxon signed-rank test is a non-parametric alternative to the paired Student's t-test for the case of two related samples or repeated measurements on a single sample.

A statistical test was proposed extending the Wilcoxon test to arbitrarily right-censored  samples. The test is particularly applicable to comparing two survival distributions in a
clinical trial when there is a mixture of individuals who have died and others who are still alive in each group.