The Tukey test limits familywise error by ______.

A) changing the degrees of freedom
B) placing limits on the number of groups that can be in a research study
C) changing alpha from .05 to .10 for each analytical comparison
D) increasing the critical value of the statistic needed to reject the null hypothesis for each comparison

The Tukey test controls the familywise error rate by increasing the critical value of the statistic needed to reject the null hypothesis for each comparison. This means that the chance of making a Type I error (rejecting the null hypothesis when it is actually true) for any of the pairwise comparisons is reduced, thereby limiting the familywise error rate.