GraphPad Statistics Guide

Multiple comparisons tab: Three-way ANOVA

Multiple comparisons tab: Three-way ANOVA

Previous topic Next topic No expanding text in this topic  

Multiple comparisons tab: Three-way ANOVA

Previous topic Next topic JavaScript is required for expanding text JavaScript is required for the print function Mail us feedback on this topic!  

Choose your goal for multiple comparisons. On the next tab, you can choose exactly which test to use.

In many cases, the answers you really want are determined by multiple comparisons and not by the overall ANOVA analysis. Choose the comparisons you want to make on this tab, and then set the details on the next (Options) tab.

Be thoughtful about which comparisons you need to make as part of your experimental design. If you make too many comparisons, the tests become stricter and it is harder to find anything.

If you have 2x2x2 ANOVA, then the number of comparisons are:

Compare each cell mean with every other cell mean: 28 comparisons

Compare the control mean with the other cell means: 7 comparisons

Compare means that differ by only one factor: 12 comparisons

Compare each mean in row 1 with the cell mean just below it: 4 comparisons

 

If you have 2 x 2 x k ANOVA, then the number of comparisons are:

Compare each cell mean with every other cell mean: 8k2-2k comparisons

Compare the control mean with the other cell means: 2x2xk-1 comparisons