Non-parametric tests: testing when distributions are unknown.

Abstract

Abstract This chapter introduces several other commonly used non-parametric tests: the sign test, the Wilcoxon signed rank test, the Wilcoxon rank sum test, the Kruskal-Wallis test, the runs test, and Spearman's rank correlation test. Non-parametric tests do not require knowledge or estimates of the parameter values. They can be performed without uniquely identifying the distribution, or its parameters. The use of these non-parametric tests in forestry applications are given in this chapter.