NON PARAMETRIC TESTS IN BIOSTATISTICS: Mann Whitney U test, Wilcoxon signed rank, Kruskal Wallis ANOVA, Spearman rank correlation, small sample analysis reading comprehension passages. Why trust coin flips over perfect bell curves when real patient data skews wild? Students explore non-parametric tests ranking messy medical results without normality assumptions, like Mann-Whitney comparing drug trials or Kruskal-Wallis sorting multiple treatments. They uncover Wilcoxon pairing before-after scan