I have run an experiment with a 2 x 2 factorial design. From what I understand there is no need to adjust the alpha-level for multiple comparisons because all main-effects and interactions are planned.
However I have had a reviewer come back and suggest analyses of some simple effects and as a result I am starting to wonder about error-correction for multiple post-hoc comparisons.
My question is when calculating something like a Bonferroni error correction, how many comparisons should be in the formula? Should I only correct for the post-hoc tests or does doing post-hoc tests mean I should include all planned contrasts as well? So, if performing the bonferroni procedure, what should the k in $\alpha$/$k$ be for a 2 x 2 ANOVA with 2 tests of simple effects?