Post-hoc testing is implemented when...

Post-hoc testing is implemented when...

• A. Always
• B. When ANOVA reveals a significant difference among three or more groups
• C. Only for non-parametric tests
• D. Never

Answer: (B)

Post-hoc testing is a follow-up step after an analysis of variance. The ANOVA asks whether all group means are equal, and a significant result means there is some difference somewhere, but it doesn’t reveal which specific pairs differ. Post-hoc tests compare the group means pairwise and adjust for making many comparisons, so the overall chance of a false positive stays controlled. This approach is used when there are three or more groups and a significant overall effect, providing clarity on exactly which groups differ. It’s not appropriate if the ANOVA isn’t significant, and it isn’t limited to non-parametric methods.

Post-hoc testing is a follow-up step after an analysis of variance. The ANOVA asks whether all group means are equal, and a significant result means there is some difference somewhere, but it doesn’t reveal which specific pairs differ. Post-hoc tests compare the group means pairwise and adjust for making many comparisons, so the overall chance of a false positive stays controlled. This approach is used when there are three or more groups and a significant overall effect, providing clarity on exactly which groups differ. It’s not appropriate if the ANOVA isn’t significant, and it isn’t limited to non-parametric methods.