Post hoc tests are used to
uncover specific differences between three or more group means when
an analysis of variance (ANOVA) F test is significant
Post hoc tests allow researchers
to locate those specific differences and are calculated only if the
omnibus F test is significant
Post hoc tests are termed a
posteriori tests; that is, performed after the event (the event in
this case being a study).
Post hoc tests attempt to control
the experimentwise error rate (usually alpha = 0.05) in the same
manner that the one-way ANOVA is used instead of multiple
t-test