Advice: Rank Correlation and Cuzick's Trend Test


Interval (non-normal) vs. Nominal (with order)


KENDALL'S RANK CORRELATION AND CUZICK'S TEST FOR TREND: Kendall's and Spearman's methods for rank correlation are listed in the nonparametric methods section of the analysis menu. Kendall's method reflects the strength of the relationship between the variables and copes with ties much better than Spearman's method. Do not use Spearman's method if either variable is anything less than ordinal. Cuzick's test is a useful method to look for a uniform trend across several groups.