data; input teacher method $ diff; cards; 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 proc glm; classes method teacher; model diff=method|teacher/e e3 e4; run; data; input teacher method $ diff; cards; 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;