I am trying to see if I have a significant interaction between both locations of my research study. I am a SAS novice and cannot figure out the code needed. An example of my data is below if anyone can help! (I have been using SAS studio 9.4)   In my previous trials (3 way factorial) I used this code: proc glimmix data=last_rating;       class FactorA FactorB FactorC Date Rep;       model cover = FactorA | FactorB| FactorC |Date;     random Rep;       run; title 'ANOVA Percent Cover'; proc glimmix data=last_rating;  class FactorA FactorB FactorC Rep;     model cover = FactorA |FactorB| FactorC;     random Rep FactorA*Rep FactorA*FactorB*Rep;     lsmeans FactorA FactorB FactorC FactorA*FactorB FactorA*FactorC FactorB*FactorC FactorA*FactorB*FactorC / pdiff lines;     run; However, for this trial I am only looking at 2 factors (seeding interval and herbicide) but I have added a second location unlike my previous trials. Can I use location as Factor C?    Data example: TRT Seed_Int Herbicide Rep Location Date_1 Date_2 Date_3 Date_4 Date_5 Date_6 101 0 GO 1 1 45 90 95 95 100 100 102 0 SZ 1 1 45 95 95 95 100 100 103 0 AS 1 1 15 80 95 90 90 100 104 0 4XT 1 1 25 85 100 95 100 100 105 0 NON 1 1 50 100 100 100 100 100 106 3 GO 1 1 10 80 95 95 100 100 107 3 SZ 1 1 10 85 95 95 100 100 108 3 AS 1 1 10 85 90 90 95 100 109 3 4XT 1 1 15 90 100 95 95 100 110 3 NON 1 1 15 85 95 95 95 100 401 3 SZ 4 2 10 75 90 85 95 90 402 0 4XT 4 2 25 85 95 80 95 90 403 7 AS 4 2 0 60 85 80 95 90 404 14 GO 4 2 0 5 55 70 90 90 405 7 NON 4 2 0 40 80 80 95 95 406 3 4XT 4 2 10 85 85 85 95 90 407 0 SZ 4 2 15 80 75 75 90 85 408 7 GO 4 2 0 45 70 80 95 85 409 7 SZ 4 2 0 45 65 75 95 85 410 0 AS 4 2 10 30 45 80 85 70 411 7 4XT 4 2 0 30 55 75 85 80 ... View more