Modeling and Multivariate Methods - SAS

Appendix A Statistical Details 667
The Factor Models
The theme for ordinal factors is that the first level of the factor is a control or baseline level, and the
parameters measure the effect on the response as the ordinal factor is set to each succeeding level. The
coding is appropriate for factors with levels representing various doses, where the first dose is zero:
Table A.11 Ordinal Factors
Term
Coded
Column
A a2 a3
A1 0 0 control level, zero dose
A2 1 0 low dose
A3 1 1 higher dose
From the perspective of the JMP parameterization, the tests for A are:
Table A.12 Tests for A
parameter GLM–IV test JMP test
m 0 0 0 0
a13 2 1 1 0
a23 1 2 0 1
a1:b14 0 0 0 0
a1:b24 0.11111 0 0 0
a1:b34 0 0 0 0
a2:b12 0 0 0 0
a3:b13 0 0 0 0
a3:b23 0 0 0 0
a1b1:c12 0 0 0 0
a1b2:c13 0 0 0 0
a1b2:c23 0 0 0 0
a1b3:c12 0 0 0 0
a1b4:c12 0 0 0 0
a2b1:c13 0 0 0 0
a2b2:c12 0 0 0 0