# Post-hoc for 2x2 mixed design ANOVA using SPSS

I am analysing an experiment run with 20 participants using a $2\times 2$ mixed design ANOVA. The experiment has

• one within subjects variable A with two levels (a1, a2)
• one between subjects variable B with two levels (b1, b2)

The following are the results of the ANOVA analysis:

B F(1,18) = 5,84 p<0,026493 SS=1,44 MSe=0,25

A F(1,18) = 11,1 p<0,003734 SS=1,25 MSe=0,11

B*A F(1,18) = 7,16 p<0,015412 SS=0,81 MSe=0,11

Is there any reason to run post-hoc test in this context? SPSS complains about variables having less than 3 levels and, for this reason, doesn't allow me to run Post-hoc tests.

Question Is it possible to run bonferroni post-hoc test in this kind of scenario? If not, why? If yes, how to do it in SPSS?