Multiple Comparison Tests

Question 1

To determine where difference is after using ANOVA
Also called “pairwise comparisons”

Answer 1

Multiple Comparison Tests

Question 2

Performed after ANOVA (only if you find significance)
Most common
Test every difference, therefor are “exploratory”

Answer 2

Post-hoc

Question 3

Performed instead of ANOVA (a priori)
Focused only on specific comparisons
You won’t see this used very often

Answer 3

Planned Comparisons

Question 4

Divide alpha by number of statistical tests
Eg. alpha/6 = 0.05/6 = 0.008
Therefore use alpha = 0.008 for each post-hoc test
Downside is it is going to be very difficult to find significance with the alpha level that low

Answer 4

Bonferroni Correction

Question 5

Essentially unadjusted t-tests

Answer 5

Fisher’s Least Significant Difference

Question 6

Adjusted, but good balance of type 1 and type 2 error protection
Most commonly used

Answer 6

Sidak

Question 7

Divides alpha by number of comparisons

Answer 7

Bonferroni Correction