Bonferroni adjustments are necessary when making multiple comparisons to avoid inflating the Type I error rate.

The Bonferroni adjustment is designed to control the Type I error rate by reducing the critical p value for all comparisons.
true
True
false
False
You plan to test all pairwise comparisons among 4 means. What is the new critical p value after a Bonferroni adjustment to maintain an experiment-wise alpha of .05?

6 comparisons .05/6 = 0.00833
0.0083
0.0005
What coefficients would be used to compare Group 1 to the average of Groups 2-4?

false
1, 1, 1, 1
true
1, -.333, -.333, -.333
false
1, -.5, -.5, -.5
1, -.333, -.333, -.333 because the -.333's result in the average of Groups 2-4.
In an experiment with three conditions, the means are 2, 4, and 9. What would be the value of L for the coefficients 2, -1, -1?

-9
.0001
(2)(2) + (-1)(4) + (-1)(9) = -9
Are the following two sets of coefficients orthogonal? lfxx lfxx -1, 0, 0, 1 lfxx -1, 1, 0, 0 lfxx

false
Yes
true
No
The sum of the products of the coefficients must be 0 for them to be orthogonal. For these coefficients (-1)(-1) + (0)(1) + (0)(0) +(1)(0)=1
In an experiment with three conditions and 5 subjects per condition, the means are 2, 4, and 9, and the MSE is 24. lfxx lfxx Find t for the coefficients -2, 1, 1.

1.677
.01
L = 9, sum of coefficients squared is 6, n is 5, MSE is 24 and t = -9/sqrt((6)(24)/5) = 1.677.