That is, the first contrast represents the difference between group 2 and group 1, the second contrast represents the difference between group 3 and the mean of groups 1 and 2, and so on. If I had omi...That is, the first contrast represents the difference between group 2 and group 1, the second contrast represents the difference between group 3 and the mean of groups 1 and 2, and so on. If I had omitted the part of the command that specified the contrasts argument, you’d be looking at treatment contrasts here because it would have reverted to whatever values the contrasts() function prints out for each of the factors.
