random effect, fix effect in the guidance Appendix E [Regulatives / Guidelines]

posted by d_labes  – Berlin, Germany, 2008-02-07 11:14 (6263 d 22:08 ago) – Posting: # 1597
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Hello LS,

nearly correct i think.

Random effect is subject.

The rest of Proc MIXED code in the RANDOM statement is the specification that this random effect is bivariate normal distributed with mean=0 and variance-covariance matrix
|s2T     covTR|
|covTR   s2R  |

i.e. has different variabilities for test and reference as you see, and a covariance term to account for the fact that observations at the same subject are correlated.
The type= option defines the variance-covariance matrix and its parametrization.

But again see my reference cited above for a deeper insight.

Regards,

Detlew

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