To achieve the goal in different scale of Measurement:
| Goal | Interval/ratio | Ordinal | Nominal |
|---|---|---|---|
| Describe one group | Mean, standard deviation | Median; interquartile range | proportion |
| Compare one group to a hypothetical value |
One-sample t-test; Z-test: (for true variance known; or very big sample size) |
Wilcoxon signed rank test | Chi-square test |
| Compare two paired groups |
Paired t-test | Wilcoxon signed rank test | McNemar’s test |
| Compare two unpaired groups |
Unpaired/ two-sample t-test | Mann-Whitney U test | Chi-square test |
| Compare three or more p aired groups |
ANOVA repeated measures | Friedman test | Cochraine Q |
| Compare three or more unpaired groups |
ANOVA | Kruskal-Wallis | Chi-square test |
| Quantify association between 2 variables |
Pearson correlation | Spearman correlation | Contigency coefficients |
| Predict value from another measured variable |
Simple linear regression |