Named after the Dutch mathematician Bartel Leendert van der Waerden, the Van der Waerden test is a statistical test that k population distribution functions are equal. The Van der Waerden test converts the ranks from a standard Kruskal-Wallis test to quantiles of the standard normal distribution (details given below). These are called normal scores and the test is computed from these normal scores.
The k population version of the test is an extension of the test for two populations published by Van der Waerden (1952,1953).