*Empty cells;
data;
input teacher method $ diff;
datalines;
1 a 10
1 a 7
1 b 4
2 a 6
2 c 13
3 a 11
3 b 5
3 c 16
4 b 7
4 b 8
5 a 6
5 b 3
;
*Interaction model (used in handout);
proc glm;
classes method teacher;
model diff=method|teacher/e e3 e4;
run;
*Additive model;
proc glm;
classes method teacher;
model diff=method teacher/e e3 e4;
run;
*No missing cells;
data;
input teacher method $ diff;
datalines;
1 a 10
1 a 7
1 b 4
1 c 9
2 a 6
2 b 7
2 c 13
3 a 11
3 b 5
3 c 16
4 a 6
4 b 7
4 b 8
4 c 14
5 a 6
5 b 3
5 c 2
;
proc glm;
classes method teacher;
model diff=method|teacher/e e3 e4;
run;