Tag
nonparametric
9 answered questions tagged “nonparametric”. Browse and search all answers, or ask your own.
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How do you compare two classifiers across several datasets?
Means, win counts and the Wilcoxon signed-rank test each summarize per-dataset scores differently. Here is what each one tells you and which to report.
Read the answer →Dunn's test after Kruskal-Wallis: which p-value adjustment?
Whether pairwise Dunn tests need adjusting after Kruskal-Wallis rejects, and how Holm, Šidák and Benjamini-Hochberg differ.
Read the answer →Pearson or Spearman correlation: which should you use?
What Pearson's r and Spearman's rho each measure, when they disagree (curved relationships and outliers), and how to pick and report one.
Read the answer →How do you compare medians when the groups differ in shape and spread?
Why Mann-Whitney is not a test of medians when shapes differ, and how Mood's median test and a bootstrap interval compare medians directly.
Read the answer →Kolmogorov-Smirnov, t test or Mann-Whitney: which detects a change from a baseline?
What each two-sample test detects, why Kolmogorov-Smirnov misses changes in spread with small samples, and how to compare against a baseline.
Read the answer →Mann-Whitney effect size: is z/√N right, and which CI should you report?
Why z/√N is a shaky effect size for Mann-Whitney, why Fisher's z interval does not suit it, and which effect sizes and intervals to report instead.
Read the answer →t test or Mann-Whitney in small samples: how do you choose?
Why a normality pre-check is a weak way to pick a t test or a rank test with small n, what a power simulation shows, and where permutation tests fit.
Read the answer →How do you compare a short ordinal rating scale between two groups?
t test, Mann-Whitney or chi-square for a 1-4 rating item: what each one tests, how they compare in a simulation, and how to report the result.
Read the answer →What are the assumptions of the Wilcoxon signed-rank test?
Independent pairs, rankable differences and symmetry: what each assumption means, and why a non-significant symmetry test proves little.
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