I greatly appreciate your detailed explanation of these statistical tests. Your comment about Pearson's potential underestimation of nonlinear relationships is something I hadn't fully considered. I found your specific requirement for the chi-square test (minimum 5 per cell) especially helpful. Your examples clearly illustrate when each test is appropriate. In some cases, I have observed that researchers often apply Pearson's test without adequately checking assumptions of normality. This appears to be a common oversight that could compromise the findings in published studies.