Post Hoc Tests - Agricultural Statistical Data Analysis Using Stata - page 150

Table 8.2 Planned comparisons for seed treatment fungicides

CONTRAST COMPARISONS ORTHOGONAL COEFFICIENTS

1 versus 2-8 Do the fungicides work compared to

the check

7 -1 -1 -1 -1 -1 -1 -1

2-3 versus 4-8 Compare the mercuric fungicides to

the nonmercuric fungicides

0 5 5 -2 -2 -2 -2 -2

2 versus 3 Compare the different mercuric

fungicides

0 1 -1 0 0 0 0 0

4 and 8 versus 5-7 Compare nonmercuric fungicides

from company 1 to company 2

0 0 0 3 -2 -2 -2 3

4 versus 8 Compare fungicides from company

1

0 0 0 1 0 0 0 -1

5 versus 6-7 Compare older formulation (5) with

newer formulations (6-7) from
company 2

0 0 0 0 2 -1 -1 0

6 versus 7 Compare the two new formulations

from company 2

0 0 0 0 0 1 -1 0

test 5*(2.trt+3.trt) - 2*(4.trt+5.trt+6.trt+7.trt+8.trt) = 0

(( 1) 5*2.trt + 5*3.trt - 2*4.trt - 2*5.trt - 2*6.trt - 2*7.trt
- 2*8.trt = 0

F( 1, 35) = 152.88
Prob > F = 0.0000

test 2.trt - 3.trt = 0

( 1) 2.trt - 3.trt = 0

F( 1, 35) = 17.67
Prob > F = 0.0002

test 3*(4.trt+8.trt) - 2*(5.trt+6.trt+7.trt) = 0

( 1) 3*4.trt - 2*5.trt - 2*6.trt - 2*7.trt + 3*8.trt = 0

F( 1, 35) = 29.12
Prob > F = 0.0000

test 4.trt - 8.trt = 0

( 1) 4.trt - 8.trt = 0

F( 1, 35) = 2.83
Prob > F = 0.1016