REPEAT or RANDOM in Proc Mixed?

[Jerrya00]

Recently I am learning to use Proc Mixed and found it's so confusing about selecting REPEAT or RANDOM. Sometimes they both produce the same results. Is there anyone to be able to help? Thank you.

[SteveDenham · Accepted solution]

This is covered extensively in the text SAS for Mixed Models, 2nd ed. by Littell et al.  I strongly recommend that you get a copy as it will cover this, and much more that you will need to know.

Steve Denham