Does the Tukey HSD test correct for multiple comparisons?

Question

After performing an ANOVA and then doing post hoc tests with a Tukey HSD test is it still necessary to correct for multiple pairwise comparisons or is that done already?

Answer 1

It is not necessary to correct for multiple comparisons when using Tukey's HSD. The procedure was developed specifically to account for multiple comparison and maintains experiment-wise alpha at the specified level (conventionally .05). Page 210 of Maxwell and Delaney's book on experimental design has explanations and examples of the procedure.