Hypothesis tests are parametric tests when they assume the population follows some specific distribution (such as normal) with a set of parameters. If you don't know whether your data follows normal distribution or you have confirmed that your data do not follow normal distribution, you should use nonparametric tests.
Origin provides support for the following X-Functions for non-parametric analysis, they are available in OriginPro
| Name | Brief Description |
|---|---|
| signrank1 | Test whether the location (median) of a population distribution is the same with a specified value |
| signrank2/sign2 | Test whether or not the medians of the paired populations are equal. Input data should be in raw format. |
| mwtest/kstest2 | Test whether the two samples have identical distribution. Input data should be Indexed. |
| kwanova/mediantest | Test whether different samples' medians are equal, Input data should be arranged in index mode. |
| friedman | Compares three or more paired groups. Input data should be arranged in index. |
As an example, we want to compare the height of boys and girls in high school.
//import a sample data newbook; fname$ = system.path.program$ + "Samples\Statistics\body.dat"; impasc; //Mann-Whitney Test for Two Sample //output result to a new sheet named mynw mwtest irng:=(col(c), col(d)) tail:=two rt:=<new name:=mynw>; //get result from output result sheet page.active$="mynw"; getresults tr:=mynw; //Use the result to draw conclusion if (mynw.Stats.Stats.C3 <= 0.05); //if probability is less than 0.05 { type "At 0.05 level, height of boys and girls are differnt."; //if median of girls height is larger than median of boy's height if (mynw.DescStats.R1.Median >= mynw.DescStats.R2.Median) type "girls are taller than boys."; else type "boys are taller than girls." } else { type "The girls are as tall as the boys." }