Discovering Statistics Using IBM SPSS Statistics, 5th Ed. Practice Test

Pairwise comparisons focus on differences between two means at a time. After an ANOVA shows that at least one group mean differs, pairwise tests examine each possible pair of groups (for example, group 1 vs group 2, group 1 vs group 3, and so on) to identify exactly which means differ. Because several comparisons are made, researchers usually apply adjustments (like Tukey or Bonferroni) to keep the overall chance of a false positive under control. This approach directly captures differences between two means at a time, which is what pairwise comparisons are designed to assess. The other ideas describe different analyses: comparing all group means at once is an omnibus or global test, assessing relationships between two variables refers to correlation or regression, and testing equality of variances concerns variances rather than means.