Contrast vectors

[massaraevi]

Hello,

I am a new user of the package NanoStringDiff. I am working on an experiment with 4 groups and I am trying to figure out how to design the contrast vector, specifically which numbers to use for each group. To the best of my understanding, "0" omits the group, and the numbers, "1,-1" are used in the examples of the package. Should I use "-1/2, 1/2" for the other 2 groups? Is there any chance that 1/2 takes the average of the corresponding group? In other words, how to decide which numbers to use for the contrast vector if we have more than 2 groups?

Thank you