Pearson correlation, Spearman’s rho, and the Chi-square test are used to find out if two things are related or not. The first one, pearson correlation is applied when both variables (dependent and independent) are numbers, and the data is normally distributed (shaped like a bell curve). It verifies how strong the relationship is or if the relationship is modest and insignificant. Second, spearman’s rho is used when the data is not normal or when the numbers are ranked (like first, second, third). It looks at if one value goes up when the other does the same, even if the change is not steady. Third, chi-square test is used for categories (like colors or yes/no answers) to see if two groups are connected. For each test there are some rules: Pearson needs normal data and numbers; Spearman works with ranks or non-normal data; Chi-square needs enough data in each group and no repeated values. Finally, identifying and picking the suitable test help researchers understand the connection between variables better.