 What is the choice of statistical test for paired or matched observation? We have this scenarios of pre and post intervention. We need to do this paired or matched observation statistical tests. When we are comparing a variable where we have two outcomes, then we need to go for McNamar's test. For example, anemia present and absent before intervention and anemia present and absent before intervention, then we need to go for McNamar's test. Categorical variable more than two outcomes, then we should go for Cochrane Q. If those outcomes are ordered outcomes, then it is an ordinal variable, then we should go for Wilcoxon signed rank test. Then the same Wilcoxon signed rank test is used when we are using pre and post tests for numbers that is quantitative variables. We are using this Wilcoxon signed rank test when it is a nonparametric situation. If the distribution is normal, then we go for this parity test when we are comparing more than two observations for the parametric group similar to ANOVA, we have repeated measures ANOVA more than two measurements. The nonparametric statistical test is the Friedman's test or F test.