Sunday, October 28, 2007

Parametric vs Nonparametric

Independent t-test vs Mann-Whitney test, Wilcoxon rank-sum test

Paired t-test vs Wilcoxon signed rank-sum test

1-way ANOVA vs Kruskal-Wallis test

2-way ANOVA vs Friedman test

Pearson correlation coefficient vs Spearman R, Kendal Tau or Gamma coefficient

1 comment:

BasiaBernstein said...

Non-paramteric statistical procedures are less powerful because they use less information in their calulation. For example, a parametric correlation uses information about the mean and deviation from the mean while a non-parametric correlation will use only the ordinal position of pairs of scores. perason correlation