PROC MIXED DATA=RBC; CLASS SEASON CELL TRANSECT MATERIAL; MODEL LMBC LMBN LMBP LAPA LBISP LBGA LLAP LNAG LACDO LANCDO LPMN LPMP LNENZ LPENZ=SEASON CELL TRANSECT MATERIAL SEASON*CELL SEASON*TRANSECT SEASON*MATERIAL CELL*TRANSECT CELL*MATERIAL TRANSECT*MATERIAL SEASON*CELL*TRANSECT SEASON*CELL*MATERIAL CELL*TRANSECT*MATERIAL SEASON*TRANSECT*MATERIAL SEASON*CELL*TRANSECT*MATERIAL; RANDOM SEASON TRANSECT SEASON*CELL SEASON*TRANSECT SEASON*MATERIAL TRANSECT*MATERIAL SEASON*CELL*TRANSECT SEASON*CELL*MATERIAL CELL*TRANSECT*MATERIAL SEASON*TRANSECT*MATERIAL SEASON*CELL*TRANSECT*MATERIAL; LSMEANS SEASON*CELL SEASON*TRANSECT SEASON*MATERIAL CELL*TRANSECT CELL*MATERIAL TRANSECT*MATERIAL SEASON*CELL*TRANSECT SEASON*CELL*MATERIAL CELL*TRANSECT*MATERIAL SEASON*TRANSECT*MATERIAL SEASON*CELL*TRANSECT*MATERIAL/pdiff cl adjust=TUKEY; RUN;   This one is my SAS statement. The following is the error in LOG.     547! CELL TRANSECT MATERIAL SEASON*CELL SEASON*TRANSECT SEASON*MATERIAL CELL*TRANSECT 547! CELL*MATERIAL TRANSECT*MATERIAL SEASON*CELL*TRANSECT SEASON*CELL*MATERIAL 547! CELL*TRANSECT*MATERIAL SEASON*TRANSECT*MATERIAL SEASON*CELL*TRANSECT*MATERIAL; ERROR 73-322: Expecting an =. ERROR 22-322: Syntax error, expecting one of the following: a name, ;, (, *, -, /, :, @, _CHARACTER_, _CHAR_, _NUMERIC_, |. ERROR 200-322: The symbol is not recognized and will be ignored. 548 RANDOM SEASON TRANSECT SEASON*CELL SEASON*TRANSECT SEASON*MATERIAL TRANSECT*MATERIAL 548! SEASON*CELL*TRANSECT SEASON*CELL*MATERIAL CELL*TRANSECT*MATERIAL SEASON*TRANSECT*MATERIAL 548! SEASON*CELL*TRANSECT*MATERIAL; 549 LSMEANS SEASON*CELL SEASON*TRANSECT SEASON*MATERIAL CELL*TRANSECT CELL*MATERIAL 549! TRANSECT*MATERIAL SEASON*CELL*TRANSECT SEASON*CELL*MATERIAL CELL*TRANSECT*MATERIAL 549! SEASON*TRANSECT*MATERIAL SEASON*CELL*TRANSECT*MATERIAL/pdiff cl adjust=TUKEY; 550 RUN;     ... View more

Yes, Duncan does not give the interaction mean separation.  I tried to get the interaction mean separation by LSMEANS and TUKEY but could not succeed. Could you please give me an example of SAS statement for the following example. Four-factor design Seasons (2 levels) random Sites (4 levels) fixed Depths (4 levels) random positions (4 levels) fixed.  and we have some missing values in the data set.  Thanks, PaigeMiller again for your replies.    ... View more

Thank you PaigeMiller. I understand your point. My second question was how to compare the interaction means? Because Duncan and Tukey test only give the mean effect separation but not the interactive mean separation?  ... View more