4. Univariate non-parametric methods
4.1 Wilcoxon signed-rank test
Overview The Wilcoxon signed-rank test was described by . It is designed for the situation where ...
4.2 Example: Plankton hauls
An example of a paired design with two groups is provided by , who described a study by to inves...
4.3 Mann-Whitney U test
Overview The Mann-Whitney U test was described by and . Here, interest lies in comparing two gro...
4.4 Example: Snapper in marine reserves
As an example of the Mann-Whitney U test, we will look at a dataset consisting of counts of the s...
4.5 Kruskal-Wallis test
Overview The Kruskal-Wallis test was described by and . Its purpose is to compare two or more in...
4.6 Example: A bivalve species from Ekofisk
We will use the Kruskal-Wallis test to compare counts of a bivalve species, Abra prismatica, occu...
4.7 Kolmogorov-Smirnov test
Overview The Kolmogorov-Smirnov test is a non-parametric test for comparing two distributions of ...
4.8 Example: Sizes of oysters
To demonstrate the Kolmogorov-Smirnov test in PRIMER, we shall return to the dataset consisting o...
4.9 Test of Association
Overview PRIMER 8 offers several options to achieve a non-parametric bivariate test of associatio...
4.10 Example: Ekofisk diversity
To demonstrate the test of association, we shall re-visit a dataset of macrofauna assemblages col...
4.11 Example: Associations between species
It is instructive to consider some additional examples of the test of association where the varia...