Complex sentence: In statistics, the Siegel-Tukey test is a non-parametric test, which applies to data measured at least on an ordinal scale, and it also tests for the differences in scale between the two groups.
Split into simpler sentences: In statistics, the Siegel-Tukey test is a non-parametric test, which applies to data measured at least on an ordinal scale. It tests for the differences in scale between the two groups.