Sci Advisor P: 3,295 I'm not an expert on this, but I was curious enough about the table to look up "Dunn Test" and found: http://www.google.com/url?sa=t&rct=j...NAkXpw&cad=rja In the slide "What is a contrast anyway", it is explained that a contrast is a linear combination of means. For example, if the hypothesis $\mu_A = \mu_B$ is true then the contrast $1 \mu_A + (-1) \mu_B = 0$. So I suspect the table gives you the coefficients (such as 1 and -1) that are involved in the contrast being tested. I don't know anything else about the subject.