I've been reading up on sliding differences coding (forward differences coding, on the ucla page: http://www.ats.ucla.edu/stat/r/library/contrast_coding.htm).
Here is the contrast matrix recreated below:
A vs B B vs C C vs D
A 3/4 1/2 1/4
B -1/4 1/2 1/4
C -1/4 -1/2 1/4
D -1/4 -1/2 -3/4
I don't quite understand why the comparisons are as they are. If I saw this matrix, I would have assumed at first glance that the first comparison is between A and the mean of B,C,D; the second comparison is between mean of A and B compared to the mean of C and D; etc.
Can someone explain this to me?
Thanks!