When computing individual confidence intervals based on the t distribution for all possible pairwise comparisons of the treatment group means,the experimentwise error rate will be
A)equal to $\alpha$ .
B)less than $\alpha$ .
C)greater than $\alpha$ .

Question

Quizplus · Accepted Answer

When computing individual confidence intervals based on the t distribution for all possible pairwise comparisons of the treatment group means without adjusting for multiple comparisons, the experimentwise error rate (the probability of making at least one Type I error across all comparisons) will be greater than the nominal alpha level ($\alpha$) for any single comparison. This is because each additional comparison increases the chance of making at least one Type I error across the entire set of comparisons.

When Computing Individual Confidence Intervals Based on the T Distribution α\alphaα

When Computing Individual Confidence Intervals Based on the T Distribution $\alpha$