Communication Research: Post Hoc Test

$q = \displaystyle \frac {\text{the difference between any two means}}{\text{the standard error of the difference between any two means}}$

$q = \displaystyle \frac {\overline{X_i}-\overline{X_j}}{\text{se}}$

$se = \displaystyle \sqrt{ \frac {Var_{by error}}{n} }$
$se = \displaystyle \sqrt{ \frac {MS_{error}}{n} }$

cf.

$t = \displaystyle \frac {\text{the difference between any two means}}{\text{the standard error of the difference between the two means}}$