When doing planned comparisons, _________.
A) there is no correction for the inflated Type I error probability
B) a different number of df are used which corrects for the inflated Type I error probability
C) t obt is reduced to correct for the inflated Type I error probability
D) a different sampling distribution is used to correct for the inflated Type I error probability

Question

Quizplus · Accepted Answer

Planned comparisons (or planned contrasts) involve specifying hypotheses for specific comparisons before the data are collected. These comparisons do not adjust the critical value or the degrees of freedom to correct for the inflated Type I error probability that comes from making multiple comparisons. Instead, they rely on the pre-experimental design and hypotheses to limit the number of comparisons, thus inherently controlling the Type I error rate to some extent. However, they do not use any statistical adjustment (like Bonferroni or Tukey adjustments) directly within the test itself to correct for this inflation.

When Doing Planned Comparisons, _________