Statistics:  Choosing a Test

DATA            TYPE            GROUPS  TEST(S)
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Nominal         Independent     2       Chi Square, Fisher's Exact
Nominal         Paired          2       McNemar
Nominal         Independent     >2      K-sample Chi Square
Nominal         Paired          >2      Cochran's Q
Ordinal         Independent     2       Wilcoxon (Rank Sum), Mann-Whitney U
Ordinal         Paired          2       Wilcoxon Signal Rank, simple sign test
Ordinal         Independent     >2      Kruskal-Wallis ANOVA (special ANOVA)
Ordinal         Paired          >2      Friedman's 2-way ANOVA (special ANOVA)
Interval        Independent     2       Student's T test
Interval        Paired          2       Matched-pair T test
Interval        Independent     >2      ANOVA, multiple comparisons, planned
                                         analysis
Interval        Paired          >2      repeated-measures ANOVA

Use Yates' correction for continuity if <10 in a square

Correlation  Techniques
Nominal         Inependent      2       contingency coefficient
Ordinal         Independent     2       Spearman's Rho
                                        Kendall's tau
Interval        Independent     2       Pearson's r