Hush hush baby [Design Issues]

posted by ElMaestro  – Denmark, 2013-04-08 14:23 (4829 d 19:38 ago) – Posting: # 10369
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Dear d_labes,

❝ I would expect some inter-subject (co)variance terms on each off-diagonal element like that for 'normal' replicate designs, f.i. partial replicate (written for the sequence TRR, heterogeneous compound symmetry parametrization):

       T            R            R

T  s2bT + s2wT  rho*sbT*sbR     s2bR

R  rho*sbT*sbR  s2bR + s2wR     s2bR

R  rho*sbT*sbR    s2bR       s2bR + s2wR

s2bT=between variance of T, s2wT=within variance of T, sbT=sqrt(s2bT)

s2bR=between variance of R, s2wR=within variance of R, sbR=sqrt(s2bR)


This, I think, does not look right; e.g. lower left and upper right should be identical; I would possibly put rho*sbT*sbR top right if the solution with rho is desired. I never understand why we want a rho but what do I really know?!?

The zeros elsewhere applies whenever two observations are from different subjects. Note that I speak of V (=ZGZt+R), rather than G or R alone. Anyways, for the case of three treatments (2 R's and one T) V will, assuming data are ordered by subject, have such blocks as you suggest diagonally and zeros elsewhere.

Pass or fail!
ElMaestro

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