Most inferential statistical methods are parametric, requiring normally distributed populations with specific parameters such as the mean, standard ...

Ranking is a nonparametric assessment method that organizes data according to specific criteria, for instance, from best to worst or heaviest to ...

The sign test is a nonparametric method for evaluating claims about simple random data from matched pairs, nominal data, or assertions regarding the ...

Consider the data on hamsters' speed before and after administering a stimulant, which constitutes a matched pair. How does one test the claim that ...

Nominal data, consisting of non-orderable names, labels, and categories, only allows for population proportions analysis. Given that the data is nominal, ...

In a class of 100 students, 60 scored a grade of less than 45 on a test, 15 scored 45, and 25 scored more than 45. This simple random data, drawn from a ...

Consider the dataset of fasting blood sugar levels of patients for two consecutive months. How does one test the claim that there is no difference between ...

Consider an example of a novel rice variety genetically modified to produce longer rice grains. To know if the grain length of the novel variety is ...

Wilcoxon rank-sum, or the Mann-Whitney U, is a nonparametric test used to determine the difference between two populations by comparing their medians. It ...

Bootstrapping is a resampling method that uses samples randomly drawn from the already collected sample with replacement. Imagine a paleontologist trying ...

In many cases, the distribution of the population from where the random samples are drawn is often unknown or difficult to determine. In these cases, the ...

Spearman's rank correlation is a nonparametric test used to find the association between two variables in paired data. Consider an example of finding ...

Consider an example where 35 pieces of vintage porcelain teacups are ranked independently by an artisan and an ordinary buyer. Kendall's tau test can ...

The Kruskal-Wallis, or H test, is a non-parametric alternative to one-way ANOVA. It effectively tests the null hypothesis that three or more populations ...

The Wald-Wolfowitz runs test examines the randomness in ordered or sequential data. It uses computed runs from the data, where the randomness is rejected ...

A scientist collected data on the body lengths of 30 baboons approaching a water source. So, the Wald-Wolfowitz test can determine if the sequence in ...

The Behrens-Fisher test assesses mean differences between two groups with disparate variances. It is especially effective for small samples, where ...

Fisher's exact test determines the significance of a nonrandom relationship between two categorical variables in a two-by-two contingency table. ...

Friedman's two-way Analysis of Variance by ranks evaluates differences among related groups. It is ideal for data that is ordinal or not normally ...

Cochran's Q test is used when the same individuals in the data are tested repeatedly for the presence or absence of an attribute. For example, 24 ...

McNemar's test applies to paired nominal data presented in two-by-two contingency tables. This is a special case of randomized block design, where ...

Kendall's coefficient of concordance is a nonparametric statistic test that measures the agreement among ranks of the variables. It assesses the ...