For a planned SINGLE comparison, the CI of can be interpreted as , in which . The and should be defined according to the denominator of .
For post hoc multiple comparisons, the CI of can still be interpreted as , wherein indicates the number of sub-groups whose means are compared. Note that qtukey(...) and ptukey(...) is defined with a two-tailed probability while qt(...) and pt(...) with a single-tailed one.
To verify it with a single click